Introduction: Kill Bedbugs With Your Christmas Lights

Picture of Kill Bedbugs With Your Christmas Lights

Santa's been checking his list, and every last bedbug is on the naughty list! 
This year, Santa has a present for all bed bugs: HOT DEATH!!

Bedbugs are nationally in the news this year, and I have encountered them in a hotel that I use for business travel. I avoided bringing the bugs home by building my last bedbug killing machine for my luggage (

Why do you need to treat your luggage for bed bugs? Simple. If you happen to be staying in a place that has bedbugs, it's possible for them to hide in the seams of your luggage, which apparently is a favorite place for them to hide after feeding. This can happen in any kind of hotel (in my case, a good-quality business hotel I had stayed in many times before) and it can still happen even if you check the room for bed bugs. I checked, didn't find any, and was still bitten on the first night I was there.

Like my last project, this one uses heat to kill bedbugs. It's similar in operation to commercially available products like the Packtite ( using a heat source in a heat chamber to raise the temperature of items to 125F to kill bed bugs and their eggs.

There was a lot of discussion on my last project - someone called it a "Hacktite" - and people were concerned about the amount of wiring that was necessary and I was thinking about an improved version. Fortunately, inspiration struck while I was hanging my Christmas lights...

Why Christmas lights? I needed a heat source that could put out between 350-400 Watts of evenly distributed heat. Hotplates and hairdryers put out too much heat; and things like room heaters don't have thermostats that go up to 125F. Christmas lights are perfect for the job!

This is a simpler project than my last bedbug killing machine, it requires only the most basic home electrical skills. This version is cheaper, and for this one you don't even need to take a trip down that weird aisle fully of funny-looking connectors at the Home Improvement store for supplies since most "big box" general retailers will have everything you need.

This project necessarily brings electricity in close contact with metal, and uses an electrical appliance (the lights) in a method for which it was not intended. You must follow all the safety precautions in this instructable. Even so, you do this at your own risk, if you have any concerns about building or using this device, please buy a commercial product like the Packtite or hire a professional Pest Control Operator instead.

Step 1: Materials

For this project you will need:
 - A 30 gallon or larger metal trashcan
 - Between 350 and 400 Watts of incandescent Christmas lights:
    - "C9" bulbs are usually 7W each and usually come in strings of 25 bulbs, making 175W per string. Start with one string initially and add a second string if it's cold outside and you need more heat. Two strings (50 bulbs) will give you 350 Watts. 
   - "C7" bulbs are usually 5W each and usually come in strings of 25 bulbs, making 125W per string. Start with two strings initially. Three strings (75 bulbs) will give you 375 Watts and might work a little better if it's colder where you live.
 - A thermometer with a remote probe
 - A thermometer with a long probe (optional, but it will help to make sure you don't destroy your luggage)
 - A christmas light timer (try to get the kind with a built-in GFCI circuit breaker)
   - If your christmas light timer doesn't have a built-in GFCI circuit breaker, then you must either have a GFCI outlet on your house to plug into, or a separate GFCI plug, or an isolation transformer available.
 - A 3-conductor extension cord (one with a ground prong)
 - A 3-prong replacement electrical plug
 - A 3/8" clamp connector for 1/2" knockout (optional, but recommended)

New safety items needed since this Instructable was originally posted:
 - A small sheet metal screw or a ground screw
If you use the wiring method:
 - A short length (about 2 feet) of green stranded (not solid) ground wire
 - Another 3-prong replacement electrical plug or a grounding adapter plug
 - A grounded power splitter (the one I'm using here is a 3-way)
If you use the almost-no-wiring method at step 2:
 - A long length of green stranded (not solid) ground wire, long enough to reach from your bedbug death chamber to the nearest copper water pipe
- A ground clamp (sometimes called a saddle clamp) that allows you to connect a ground wire to a water pipe - there's a picture of it at step 2.

 - Screwdriver
 - Drill (optional, but recommended)
 - Wire cutter
 - Wire strippers
 - If you choose to follow the "no cutting, no wiring' method at step two, you'll need a pipe wrench or similar tool with large jaws.

Step 2: Prepare the Heat Chamber

Picture of Prepare the Heat Chamber

The heat chamber for this is a 30-gallon metal trash can. The job for this step is to bring an electrical outlet to the inside of the trash can so that we can plug the Christmas lights into it.

My method:
 - Drill a 3/4" hole in the side of the can. I drilled it near the bottom as you can see, but realized later it would actually be a bit more convenient near the top.
 - Install a cable clamp in the hole.
 - Cut the end off of an extension cord near the plug end (not the outlet end). Use a 3-conductor cord. Discard the cut-off plug or store it out of reach of children.
 - Pass the cord through the cable clamp so that the outlet is in the can and the bare end is outside
 - Attach the replacement plug to the bare end of the extension cord, following the manufacturer's instructions, and paying extra-careful attention to the polarity of the wires.
 - Tighten the cable clamp.
It is important to use a cable clamp in the hole. The edges of the hole are sharp, and if the cable is not clamped then the edge of the hole will cut through the insulation on the cord and electrify the can. That would be bad.

New safety instructions since the instructable was originally posted:
Now we're going to ground the can. Even though you must protect your can with a GFCI socket outside (right!), the GFCI is actually supposed to be a secondary protection against electrical failure. The primary method should be grounding. Why? Let's say that an electrical short-circuit forms in the can (from a broken bulb, for example) and causes the live conductor to come into contact with the can. It could sit like that all day, until you touch it and it finds a path to ground through you. The GFCI is supposed to pop and cut the current under these circumstances, but not before at least a little current passes through you. It probably won't kill you. Probably.

Let's go ahead and ground the can as the primary defense mechanism against short circuits. If the can is grounded, then if there is ever a short circuit then the GFCI should pop immediately without any current having to go through you. If the can is grounded, even if your GFCI fails, then it should pop the circuit breaker at your electrical panel.

Wiring method (see the no-wiring method section for the no-wiring method) -
 - Wire up the short length of green ground wire to the ground prong of the extra electrical plug you bought and assemble the electrical plug according to the manufacturers' specifications. Do not wire anything to the live or neutral pins.
 - Drill a small hole in the side of the can to pass the wire out
 - Wind the other end of the ground wire around a ground screw and screw it into the side of the can, as shown in the picture. I did it this way so that the point of the screw was inside the can.
 - Using the power splitter, the lights and your ground adapter must both be connected to the extension cord socket
 - Check for electrical connectivity between the can and the ground prong of the extension cord.

Alternative, no-cutting, almost-no-wiring method:
Get a big pair of pliers, a pipe wrench, or other similar item. I used my "Functional Utility Bar" in the pictures below. Use the tool to bend the rim of the can inwards by about half an inch. It's tougher than it looks. Then when you get to step 5 you're just going to snake the extension cord under the rim of the can.

New safety instructions since the instructable was first posted for the almost-no-wiring method: Strip both ends of the green ground wire that you bought to expose the copper wire inside. Insert one end of the stripped green wire to the electrical connection on the ground clamp and tighten the screw. Find a nearby copper water pipe (probably wherever you attach your hose) and clean a section of the pipe with steel wool or sandpaper until it's a bright shiny copper color and then install the ground clamp on the pipe. Wind the other stripped end of the green ground wire around a ground screw and screw it into the side of the can

Finally, drill a small hole in the side of the can near the top. You'll install the long-probe thermometer through there later.

I chose a metal can because it's low-cost, will not deform with heat, and if a fire were to develop inside the heat chamber then a metal trashcan will contain it and cut off the oxygen. Others have suggested plastic cans would be more electrically safe. Perhaps you could place the metal can inside a plastic can for the best of both worlds. If you are really worried, you should buy a commercial product like the Packtite instead.  

Step 3: Prepare Your Luggage

Picture of Prepare Your Luggage

Do this outside. You are less likely to accidentally release a bedbug into your house, you are less likely to break a bulb, and if the contents of your luggage do happen to catch on fire then you are less likely to burn your house down.

If you bagged your luggage (to prevent the escape of bedbugs while you were getting all this ready), remove the bag now.

Remove anything from your luggage that could be sensitive to heat and treat it separately. This would include medicines and electronics.

Remove anything from your luggage that would be dangerous if heated and treat it separately. This would include aerosol cans, perfume (alcohol), alcohol, lighter fluid, etc.

Remove anything from your luggage that might melt and damage something else in the luggage. This would include anything waxy, lipstick, stick deodorant, etc.

Remove any paper tags from the outside of your luggage.

Place the remote probe thermometer in the center of your luggage. We're trying to heat the coldest part of your luggage to 125F, and the outside will be hotter than the inside.

Take your strings of lights and wrap them around your luggage, trying to space the bulbs as evenly as possible around the sides of your luggage. 

Step 4: Put the Luggage in the Can

Picture of Put the Luggage in the Can

Do this outside. You are less likely to accidentally release a bedbug into your house, you are less likely to break a bulb, and if the contents of your luggage do happen to catch on fire then you are less likely to burn your house down.

Make sure the extension cord is unplugged. Plug the lights into the outlet inside the can. Then CAREFULLY lower your bulb-wrapped suitcase into the can, making sure you don't break any bulbs by doing so.

If you followed the alternative method at step 2, then you're going to place your extension cord at the part of the rim you bent earlier, so that you can put the lid on the unit with the cord under the rim.


Step 5: Fire It Up

Picture of Fire It Up

Do this outdoors. Choose a dry day with no risk of rain. Do this in an area where the device cannot be knocked over or disturbed by pets or children or anyone.

Plug the Christmas light timer into an electrical outlet on your home.  Either the timer or the outlet must have a GFCI protector on it. Test the GFCI protector according to the manufacturer's instructions.

Set the timer to "on". Plug the extension cord from the can into the outlet on the timer.

Set the timer for 2 hours. If it's light outside then you may need to cover the timer with an empty coffee can or what-have-you to "fool" the timer into thinking it's dark out.

Check that you have no broken bulbs or any other unsafe condition in the can.

Install the long-probe thermometer through the hole in the can you drilled earlier. Make sure the end of the probe is not touching the side of the can.

Place the lid on the can. If you followed the alternative method at step two, be sure you've got a medium-tight fit between the rim of the can and the lid, tight enough to hold the cord in place, but not so tight you're going to damage the conductors or insulation in the extension cord.

Step 6: Monitor Often

Picture of Monitor Often

Monitor the temperature often. You are aiming for 120F on the long-probe thermometer, and 125F on the remote probe thermometer. This is contrary to previous advice I had given when I first wrote the instructable - I realized that the air temperature inside the can is lower than the temperature inside the luggage.

It will take a little while for the can to heat up initially, but you really don't want the temperature inside the can (measured by the long-probe thermometer) over 130F. Remember that environmental factors like wind (or still air) can affect the temperature in the can, so it could hover at one temperature for an hour or more and then change temperature - for me it seems that it can hover for the first hour ot two and then rise 25degrees or so in a few minutes as it gets close to the end of the heating process.

If the long-handled probe goes over 130F, unplug the device, wait for it to cool, remove your bag from the can, and remove a string of lights, and go back to step 3.

If the long-handled probe can't get up over about 100F then the internal contents of your luggage cannot get up to 125F. Unplug the device, remove your bag, and go back to step 3 but add another string of lights.

Experiments with this can show it takes 2 to 2 and a half hours to get the temperature measured by the remote probe in the center of the luggage to 125F

Step 7: 125F and You're Done

Picture of 125F and You're Done

When the internal temperature of your luggage reaches 125F, you're done, and whatever bedbugs may have been living in your luggage are now dead.

Unplug the unit, and wait for everything to cool. The waiting period is important here, it makes sure that if there does happen to be a cooler spot in your luggage that the heat can soak in there well too.

Remove your luggage, unwrap the lights carefully, and store the device. Use it after every trip!

I am not a bedbug entymologist, but most of the advice I see on the 'net says temperatures between 115F and 125F are sufficient for killing bedbugs, with less time required at higher temperatures. While this research indicates 7 minutes at 114.8F is sufficient:  , other research indicates 125F is required for instant death of bed bugs. I'm going with 125F.

Other similar devices:
 - The only small-scale, UL-Listed consumer bedbug killing heater that I'm aware of is the Packtite. Like this project, it's intended for small amounts of luggage or other items, and someone else builds the Packtite for you and guarantees its safety. There could be others.
 - The University of Florida has been experimenting with a larger version:


AnneW41 (author)2016-06-29

I am desperate to get rid of the bed bugs infesting my house, is this effective? anyone try it? i know that heat is a good choice but i dont want to burn my house to the ground... is that dramatic? i read another blog and they suggest a DIY bed bug heater. do they work? Help please, these bugs are sucking the money from my purse faster then the blood from my arms!

marcgr (author)AnneW412016-06-29

Only for a suitcase-sized bunch of clothes at a time. It sounds like your problem is bigger than that.

I used it a couple of times when my employer made me stay in a hotel that I know has bedbugs (I found one in my room). I used bedbug-safe practices (do not put luggage on the bed - always use the luggage rack - make sure you don't transfer bugs from the bed to your luggage in your pyjamas etc) and then I also used this. I never had bedbugs in my home afterwards so I don't know if it's the bedbug-safe practices or the heat from this device that protected me.

AnthonyR129 (author)2016-06-22

It looks like a Christmas bomb tbh

ReaganC1 (author)2016-03-08

This idea freaks me out! Maybe it is because the lights have to get scary hot to even do anything. I'll just stick with my yikes. i 'm all for DIY but honestly this just seems crazy.

David Hoskins (author)2015-10-21

I just reread this again and the info at the end is totally wrong.

If 114F for 7 minutes killed bedbugs getting rid of them here in Arizona would be the simplest thing in the world. It regularly gets over 120 here in the valley. I tried to kill the bedbugs off at my house by turning the air off and leaving all the curtains open on a day when it got up to 118F.

The house was over 125F inside when I got home that afternoon. I took off for the night and go make a long story short. I got about a week reprieve before I started getting bitten up again.

The exterminator I wound up hiring told me that bedbugs have tolerances that are very similar to humans. (Makes sense since we are their favorite food.) Locking a healthy person in the house that day would have made them very uncomfortable but wouldn't be enough to kill them. Same for the bugs.

If you did have bedbugs in your luggage all you would have accomplished would have been to make them mildly uncomfortable for a little while.

David Hoskins (author)2015-10-21

A quick warning for anyone using this method.

In order to kill bedbugs and their eggs you need to expose them to temperatures over 120F for 12 consecutive hours. If you can get the temperature over 120F less time is required though I am unsure of the ratio.

I know the adult bugs die off in a shorter time frame, the newts, (baby's), and eggs will consider anything under 12 hrs to be a minor inconvenience. It doesn't sound like there was enough time in the original scenario for them to reproduce. Keep in mind that bedbug eggs can lie dormant for 18 months, they are also asexual which means that a single egg can hatch and result in a full blown infestation down the road.

Alcohol as one poster recommended does absolutely nothing save giving them a buzz. I've personally sprayed a bedbug with 90% isopropal, dropped the same bug into a small dish of 90% isopropal, and watched as it swam its was to the edge and climbed out. The only way using alcohol will kill bedbugs involves a lighter or matches.

In fact some of the commercial traps use benzyl alcohol as a lure!

ChippMarshal (author)2014-01-10

Absolutely brilliant! People often have items that can't be treated in the dryer or with insecticides. Most places recommend putting the items in a plastic bag and using the heat or cold (depending on the season) to kill the bed bugs. Unfortunately, we can't always get the temperatures hot enough (or cold enough) to get the job done. This is a wonderful solution. Very impressive.

Dr.Bill (author)2013-12-16

I used diatomaceous Earth. DE is very sharp. The bugs crawl through the stuff picking up the DE. The DE works it's way into the joints of the bug and cuts them to ribbons internally.

marcgr (author)2011-12-21

Instructable updated!

I have now added instructions for grounding the can. If you have already built one of these, PLEASE look at the new instructions and add a ground. It only took a few minutes to do. This is for your safety, do it before you next use it!

Also some experiences:

I am mostly using ONE strand of lights and getting the air temperature in the can to 100-120F. That's still enough to get the luggage contents to 125F. The temperatures I was using earlier (150F-175F) were melting some of the plastic parts on my luggage.

Dan39 (author)2010-12-19

GFCI will work fine without ground

GCFI will work fine with only 2 prong and no ground. GFCI does not use the ground to detect fault. a GFCI trips when the hot wire current and neutral wire current are not equal. when a ground fault happens, current goes from the hot and straight to ground, causing more current to go through hot than neutral, and the GFCI trips.

marcgr (author)Dan392010-12-20

Actually you guys are both right... Originally I was thinking like Dan39 on this.

After thinking some more I realized that if a bulb breaks or if the insulation on the lights fails, and if the can subsequently becomes electrified, then the can could actually stay electrified and the GFCI won't trip immediately. Then whoever happens to touch the can would become the path to earth and THEN the GFCI would trip.

It would probably hurt a bit and probably wouldn't be fatal to a healthy adult, but they keyword here is probably. I will update the instructable later this afternoon to include a ground for the can.

marcgr (author)marcgr2011-12-21

Took a little time to get around to it... just did the big update...

putty1cat (author)2011-10-12

A large car on a hot day in a hot country would do your mattress even! Or what about a green house?

Utahtabby (author)2011-05-13

Wouldn't it make sense for all airports, hotels, trains and bus stations to have some sort of mechanism, sterilizer, etc., to make all the luggage and cargo go through before you can arrive/board and/or off-load/leave? Something that would work quickly? Seems like if they can invent machines for the TSA to force us through like cattle to check us out at airports and since they scan luggage anyway, someone should invent a bedbug death ray.

samtulana (author)2011-01-24

This can be done yourself or you can buy?

kareee (author)2011-01-19


ice_k99 (author)2010-12-19

Couldn't you just buy some dry ice and put it above the container your luggage is in? Death by CO2 poisoning, and cold too.

marcgr (author)ice_k992010-12-20

I don't know how long bedbugs can live in the absence of oxygen and a quick google doesn't tell me. My gut feel is that it could be quite a long time... bedbugs can live for 18 months without food, I have to think they could survive without respirating for a while.

You'd also have to consider whether CO2 would kill any eggs that might have been laid in your luggage, my guess is probably not.

You're on the right track though. Is there any other gas that could be used to gas bedbugs to death? Vikane gas has been shown to do it (it's the same gas used by professional pest control operators when they "tent" a house for termites)... It's also quite deadly to humans as well unfortunately.

Can anyone think of an effective and safe way to gas bedbugs to death?

ice_k99 (author)marcgr2011-01-02

Good retort. The eggs...those damn eggs! I'd imagine they would survive, too. Those eggs might as well be acorns considering the resilience of the properties of the eggs. Alcohol resistant, really? damn.

But who knows, I'm sure there has to be some case studies which yield the appropriate information regarding low temperatures and lack of has to think about what makes an egg triggers it's birth?

Two years is a long, long time for anything to lay dormant. I guess in comparison to the cicada insect, it's nothing..

paqrat (author)marcgr2011-01-02

I don't know how long bedbugs can live in the absence of oxygen either but I don't think ability to live without food equates into the ability to live without respiration. I've thought for years, but have yet to try it, that dry ice might be a good, safe way to kill off flea infestations.

Gary Viveiros (author)2010-12-28

All you need to kill bedbugs is to shoot the heck out of the mattress with a squirt bottle filled with regular 70% isopropyl alcohol. Do this when you are absolutely sure that there is no open flame from a gas pilot light from a gas hot water heater, stove or dryer in the house and that no one will be lighting up for smoking, torching, or gas-soldering. Best way is to shoot it in the morning and then go to work or out to do errands, then come back a few hours later and open up the place and air it out - with a fan if need be. Don't stay inside with the concentrated fumes. You will get used to them and think everything is OK when it isn't (where your lung health is concerned). Stay outside until the level of the fumes abates. For bad infestations, you will want to repeat this in a couple of days when any eggs hatch. The egg coating is resilent and resistant to the alcohol, but the hatched bugs, aren't. We figured that our infestation came from a large stuffed animal purchased at a common retailer. Our landlord turned us on to using isopropyl alcohol in a squirt gun to shoot mosquitos and flies out of the air, kill cockroaches, and to treat bedbug infestations. I hate to say it, but shooting the flies and mosquitos is almost like a video arcade game. You just have to use restraint and not go wild and risk shooting someone, or over food or important receipts or papers. The worst thing you could do is sanitize your house where it hits. Personally, I use an old X-14 bathroom cleaner squirt bottle with variable spray-to-stream head because the rubber O-ring on the plunger is made stronger to handle the harsher chemical, so the alcohol doesn't affect it. You can adjust the 'spread' of the stream with the adjustable head so you can use a 'wide' pattern if there are a bunch of mosquitos or flies bothering you, or you can narrow it down to a strem to pick one off your arm or the table - kinda like a shotgun theory, I guess.

mickryobe (author)2010-12-19

This is a question nor a comment.
I have heard that diatomaceous earth will kill almost all insects including bed bugs.
Does anyone have any information about this?


Pilgrimm (author)mickryobe2010-12-19

Just want to add my 2 cents.... Diatomaceous Earth (DE) is miraculous on fleas!! I took my 2 cats to the vet, and 2 weeks later discovered that I had brought home an infestation of biblical proportions! 2 years later, I still have scars from flea bites around my ankles! But the DE is fantastic. Food-grade, non-toxic, dessicates any and all insects (fleas, chiggers, bedbugs, etc) can be left on the floor indefinitely, or vacuumed every 3 days and re-applied, and best of all cheap! I paid $16.00 for a 2Kg (4.4 Lbs)bag, (about the size of a medium bed pillow) and I still have some left.

And..... No More Fleas!!! Good Luck!!

cindym (author)Pilgrimm2010-12-26

Important Common Sense with DE

DE is a truely amazing thing to behold. There are some cautions to include:
a) Apply With Care Because its a sharp micro particulate, and it
can suspend in the air where we then inhale it into our delicate lungs.
Humans must be cautious to spray it or use it without combining it with
some kind of liquid or moist media such as oil or food, etc. Combine DE
and water with a sprayer, is the best way to apply, it keeps the DE from
being in the air and then you inhaling it. There are tons of sprayers
you can get, usually on the same websites or amazon. Some are
specially made for cracks and crevaces. Application is key with DE.

b) Clean-Up after applying DE can be just as toxic to lungs, as you can
stir up the dust again, avoid vaccuming it up, use a damp mop. Avoid
applying it on a carpet unless you can cover it with a drop cloth or
avoid the room for a while, etc. Its like moon dust, and will stay
suspended for some time.

b) Consumption - internal, be sure to get "food grade"... and if/when
you take it, best to also add bentonite clay and also fiber, such as
psyllium and flax seed, with AT LEAST 10 oz water with the DE mix,
and 10 oz afterwards. A good idea is to chase that with probiotics.

Thank you very much, typenamehre.
That is even more comprehensive than I could have imagined.
Now I am prepared for the little bug---s just in case.


marcgr (author)mickryobe2010-12-20

Sure enough! If you check out for ideas on Diatomaceous Earth. I have used it before myself to control pillbugs (aka potatobugs, roly-polys, woodlice) and it was quite effective.

If anyone can think of how to either protect or decontaminate a bag safely and effectively with Diatomaceous earth, your own instructable awaits you!

naomiandtom (author)mickryobe2010-12-19

It is true. Google the stuff and you'll learn more about it. It WORKS! It is finer than flour but it's microscopic sharp jagged edges cut into the critter's exoskeleton and it's body liquids leak out, causing it to die. I got rid of a house full of fleas this past summer with it. It's also ingestible by humans (get food grade de) and kills internal parasites. Great stuff.

Green Silver (author)2010-12-19

Couldn't you use the tumble drier at the launderette for clothing and bedding items?
Also you could add a CPU fan to circulate the air inside the container... Another saftey feature would be to add an Earth/ ground to the metal can incase you accidentally leave liquid in the luggage.

marcgr (author)Green Silver2010-12-20

Tumble-drying is recognized as an effective method of killing bedbugs, and there is some evidence that a hot wash will do it as well.

However there are some things that can't be washed and dried, like the suitcase itself!

Since bedbug behavior is to eat and then hide, the natural folds and crevices in the average piece of luggage are an attractive hiding place for them.

If you think you've been staying in a location that has bedbugs (or might have bedbugs), I think you need to decontaminate your luggage as well as the contents.

Final thought/warning on using a public facility like a laundrette or laundromat to decontaminate your stuff: if doing so, PLEASE make sure that you don't let any bedbugs loose in the facility. If you do that, and one of them hitches a ride home with someone else, then you just contaminated someone else, and that person could easily bring their infested bedding to the same laundromat that you use...

cindym (author)marcgr2010-12-26

HOT dryers....yes, This is a very important point folks. Here's the rub:
the new "eco" dryers and washers, are being built not to get the water or
air very hot, to save energy. And what this seems to be doing is a) rendering
dryers and washers ineffective in the fight against bedbugs/lice/etc. but also in some cases b) giving cotton mites or other bugs a nice cozy place to reproduce, making the problem worse.

My sister is a pharmd, and they tried EVERYTHING to get rid of their lice. All sorts of nasty chemicals. With professionals involved. With MD's involved.
With an entemologist. She did the homework on the dyers. They actually installed an upgrade to make their washer and dryer hotter. Hot water should be over 140 I believe to be effective. I no longer use the dryer and hang all my stuff outside. The UV from the sun kills things. Dryers or washers with silver in them can help.

sklarm (author)2010-12-19

Great project.

If I make one suggestion. A temperature controller would help hold the lights at 125F. This would avoid getting too hot and allows the user to not have to monitor the temperature.

Spokehedz (author)sklarm2010-12-19

Yeah, but putting it out of the range of most people who this would be most useful to.

marcgr (author)Spokehedz2010-12-20

My first thought when building the first instructable in this range was to try to find some donor appliance that had a thermostat in the 150F to 175F range, but I really couldn't find one; room heaters have thermostats up to about 80 or 90 degrees; hotplates and slow cookers are more up in the 200+ range.

After building the first one and realizing that the amount of power needed to heat the can was a lot less than I expected, I put the thermostat way down on the 'optional list". Given that the amount of heat this puts out (350-375 Watts) is about a quarter of what an average hairdryer puts out, and we're dealing with a pretty large volume and mass of stuff to be heated, the rise of temperature is going to be pretty slow, and I chose to monitor it manually.

But, if a thermostat makes you happy, go for it.

spark master (author)marcgr2010-12-21

heating coils in an oven, or toaster oven, or electric griddle) should go below 175 with a rheostat, you gotta experiment though. The glass envelopes are nicer since they contain the element from touching skin if you have an accident. You still get burned, but, open elements are way more destructive..

nice instructable

marcgr (author)spark master2010-12-21

I think you are right, however, I couldn't find any commercially available item with a thermostat capable of holding something in the 150 - 175F range. If you find one, please post back here!

pragmatic jim (author)marcgr2010-12-22

What about a food dehydrator?
I ran mine for an hour or so, and it crept up to almost 170 f.
It has no thermostat, but I imagine some dehydrators do.
The temperature could be adjusted by changing the amount of ventilation, but that might create a condition of uneven temperature.

I fergit about theose gizmo's (I have one) but you could not put a bag in it. And the temp range is about the high end of a dehydrator. I had plans for making one and it used (wait for it) light bulbs. One could rig up a simple rheostat or a triac circuit to limit the heat of several lamps with a circuit to a themostat. (not by me I have engineer friend I would ask, I can build I do not design).

I think the author is dead on with the lamps. There are other items but lamps seem safer and just easier to deal with, and trouble shooting a bad filiment is easy it either lights up or it doesn't.

Making a circuit that controls the voltage to the bulbs in relation to temperature is what is really needed. Not turn them on/off . If you find a crappy element dead food dehydrator , and pull the thermostat control it might work.

I doubt my bud has time but, I will ask him if he can make one up, if so I will post it.


7 or 4 watt lamps on a loop are way way better then the plans I had for the food dehydrator since they used 2-4 big lamps. The little ones, while more expensive, let you string out the heaters like a heat coil in a toaster. they heat more evenly.


spark master (author)marcgr2010-12-22

This is not my baliwick but look around for people tossing electric dryers , cause the motor died. Big giant nichrome wire elements. If you have a waste transfer place nearby go ask them if you can canabialize few dryers/ovens. If you put a few in parallel you can get the temperature down. But after reading your whole article and thinking about it; I like your Xmas lights, a simple and elegant solution. You can insulate the thing and even put some right inside the luggage. 451 degrees is the temp of spontaneous combustion I have laid paper across 100 watt bulbs and not gotten ignition, I did get charring once though.

There are places that sell appliance parts , but there technical staff may not have answers. They are used to a part number and then read a spec, not the reverse. Open coils would force you to make a double drum for safety. Nope your idea with the lights is a good one, the only other option is making a false floor and and placing the coils beneath it and then a set of stand offs (grill) to be sure the unit never touches the suitcase.

this is one I have bought many parts from them, and learned how to fix a few things as well.

the dryer is calling so

sklarm (author)marcgr2010-12-21

This temperature controller sells as a kit for $50 ($65) assembled and holds a temp of up to 255F.

joneslewis (author)2010-12-20

I haven't thought this through very hard, and I hate to discredit a very creative solution to a nasty problem (I just spent the day taking precautions against a few bedbugs we found in our house), but...

Couldn't you just put your suitcase in a large cardboard box, cut a small hole in the top, stick a hair dryer in there for 15 minutes? 120 degrees for 10 minutes will kill the evil, but I can't imagine the hair dryer could get up to 451 degrees or whatever the combustion point of the suitcase materials. Could it?

marcgr (author)joneslewis2010-12-21

Firstly, if you have seen bedbugs, CALL A LICENSED PEST CONTROL OPERATOR RIGHT AWAY. Most people cannot rid their dwellings of bedbugs on their own. If you can nip the problem in the bud today, you avoid having to throw away half your stuff and sealing the rest of it up for 18 months. It is really that bad, my Mom had to do it a few years ago.

This instructable is not going to help you if you already have an active bedbug infestation except POSSIBLY as part of an overall pest-control strategy laid out by a professional.

As for the box-and-a-hairdryer idea, if you can make it work safely, go for it. One problem you might have is heating up the inside of the box too fast for the heat to penetrate to the core of the luggage... definitely use the hairdryer on its lowest setting until you know how hot you are making it. Part of my idea of using the steel can was that if you do accidentally set fire to your luggage, then the fire is contained within the can at least and hopefully denied oxygen to keep burning.

A thought I had which combines both ideas would be to cut a hole in the can and place the nozzle from the hairdryer into the hole, hopefully keeping the hairdryer in its normal operating range while still heating the contents of the can. The can wouldn't cut off oxygen to a burning suitcase, but it would still be contained.

Perhaps even simpler would be to use an unadulterated galvanized can and heat the whole thing from the outside, for example, with a fan heater directed at it, or with a hotplate under it. I haven't tried either one of these, but if you can make one of them work, please make a new Instructable and cross-link from here!

Another thought I had was

drzcyy (author)2010-12-21

why not just spray with some insecticide? fumigation?
it's simple, fast, and cheap :)

marcgr (author)drzcyy2010-12-21

Bedbugs are notoriously resistant to pesticides, that's part of the reason why people are so freaked out about them. They are really hard to kill. There are six methods that I'm aware of:

- Heat (as in this instructable)
- EXTREME cold, for a period of days or weeks
- DDT (banned in most countries, and there is some evidence that they are resistant to it anyway)
- Vikane gas (which is really deadly to humans too, should only be used by licensed pest control operators)
- Mechanical damage, for example, with diatomaceous earth which cuts them open at a microscopic level
- Starvation - but they can survive 18 months without a meal...

zieak (author)2010-12-16

This could also be very helpful for someone battling head lice. A container like this could be used for pillows and other bulky items that also should be heated to 125 to kill the lice and nits. Neat!

marcgr (author)zieak2010-12-20

Hadn't thought of that, I don't know if lice die at the same temperature as bedbugs, but if they do, then kill away!

pfiddle (author)2010-12-20

125F = 52C degrees$
175F = 80C degrees approximately.
Good wrap-around insulation would be a great help in keeping the heat in and would speed up the process considerably.

marcgr (author)pfiddle2010-12-20

A few people have suggested wrap-around insulation.

Pros: It would mean less variability and possibly having to watch the internal temperature of the can less. You might be able to use one less string of lights.

Cons: Cost. 2 strings of lights are only to use about 4 cents of electricity per hour of operation, it would be hard to justify spending several dollars on insulation for it.

I'm pretty sure that it would require fewer lights with an insulated can. If anyone tries insulating their can, please post a comment back here with the amount of lights required to heat their can to the 150-175F range. Thanks!

Pader (author)2010-12-20

To Mickryobe.

Diatomaceous Earth is the fossilized remains of microscopic aquatic algae called Diatomes similar to chalk in appearance and is mined and crushed to a fine powder. These individual cell remains are extremely hard (and sharp), the have a hardness rating of 7 where a diamond is 9. If being used to eradicate insects, it works by the extremely sharp edges lacerating the exoskeleton of an insect moving over it and then the absorbent properties of the powder cause the lipids in the insect to dry out and thereby kill the insect by dehydration.

l8nite (author)2010-12-15

very interesting "ible". I think if you drilled a hole near the top of the can and then used a hacksaw to make it a U shape you could slice a rubber grommet in half and protect the electric cord while also not having to dedicate a cord for just the bug cooker, another trick might be a hotwater tank insulation blanket wrapped around the outside of the can to slow down the radiant heat thru the metal. and then the mind starts running, if you have more luggage on a regular basis a VERY large icechest could hold 2 or 3 suitcases, an old refrigerator or freezer box would hold even more or even a large box built from foil lined faom insulation sheets... wow.. I have to stop thinking bfore I write a book... Thank You for the mental stimulation !

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