We have a horse who is anhidrotic; that's a syndrome in which one does not sweat properly or at all. Specifically, in about the second week of July (when night temperatures stop dropping below 70F), our horse stops sweating completely. She starts sweating again at the end of September, but never as much as needed to keep her entirely comfortable.

In Florida, this is a big problem. Without being able to sweat, she can't cool herself, and so she overheats. In fact, she's developed "heaves" (similar to asthma in people) as a result of standing around blowing hard when she is overheated. Every summer when she stands around breathing heavily, she makes her "heaves" worse. We have fans and a misting system for her, but she still spends a miserable few months during the hottest part of the summer.

I got her a couple of ice wraps which attach with elastic and velcro to help keep her cooler. These have fabric cases which velcro closed, and hold sheets of ice cells, which we can swap out. The ice cell sheets themselves are inexpensive, made by a company called "Cryopak." My Other Half & I work freelance/from home, so there's usually somebody here who can swap out ice packs every few hours during the hottest parts of the day. (We also hose her down with cold water at that time.) But after a couple of weeks of daily use the velcro stopped being effective: it didn't hold the sheets inside the cases, and didn't hold the cases on the horse.

So I designed this vest which has zippers and a side release buckle instead.

This idea could probably be used for horses without anhidrosis who still need to cool quickly (endurance horses or 3-day eventers, perhaps) or even for non-equine purposes if the general shape is altered. It will probably not be terribly useful for traditional uses of ice, since it holds the ice packs at a fixed location; you can't wrap it around an injury. (Those ice wraps we originally bought are designed more for injuries, and they would work pretty well for occasional use.)

Step 1: Supplies

Materials:

about a yard of nylon non-stretchy sports fabric--this is what my husband says soccer shorts etc are made of, though I bought a thicker-and-hopefully-more-durable variety. There will be one layer of this material between the ice pack and the skin; it shouldn't block cold.
about half a yard of thick fabric to insulate the outside of the case somewhat
about 3 yards 3" wide elastic -- this will vary depending on the size of your horse's chest, or if you even want to put it on a horse.
2 zippers; I got 12" separating zippers, but as it turns out, I could have used closed-bottom zippers just as easily, I think.
3" wide side-release buckle. (I only found a 2" buckle, and you'll see how I attached it, but a 3" buckle would have been better.)

Tools:

Sewing machine and thread
Seam ripper
Scissors

Sewing machines are scary, and this one was borrowed; I didn't even have the manual. Hence, a lot of this work looks terrible (I'm sure the tension was wrong for this fabric, but *I* wasn't going to mess with it). Thankfully, this is a "garment" for a horse, and she's not going to care too much if it looks sloppy.

Step 2: Pattern/Measuring

On a sheet of posterboard, I traced around the ice sheets and added an inch to each side. I cut this pattern out of the posterboard. I added one inch because there needs to be room to insert the ice pack, as well as room to put in the seams. I fully expected to need to do a lot of futzing around with it, but as it turned out, adding an inch worked just fine for this size ice sheet.

I needed to know how much elastic I would be using. I had the ice packs strapped to the horse, and measured across her back from the front and from the back (Each of these was 20"). Then I measured around the front of her chest, from one edge to the other (36"). Then I measured around her belly, from the bottom of one pack to the bottom of the other (36"). I noted these measurements on the posterboard in their approximate locations.

I need this to be tightly against her shoulders, and not buckle outwards, so she receives the full effect of the ice. The elastic needs to be tight. I decided to remove 2" from each measurement to make sure it was snug.

Step 3: Cutting Out the Pieces

Case:
I used my posterboard pattern to cut 4 pieces of the nylon material.

I also cut 4 pieces of the insulating material; I was doubling it over. If you have something thick enough that you don't want to double it, you can just cut two pieces total.

Tabs:
I cut 4 6"x7" pieces of nylon, then cut each in half for 8 pieces of 3 1/2" by 6". These will be used as tabs to attach the elastic straps to the cases. Each tab contributes 2" to the length of the strap attached to it.

For attaching the buckle, I cut 2 6" by 7" pieces.

Straps:
There are 4 pieces of elastic:

2 x 14" across the back
1 x 30" around the chest
1 x 10" under the belly--the buckle will also go here, and the attachments for it take 12".

Step 4: Making the Cases: Starting With the Zipper

I recently read a great way to attach zippers, so that's the method I used.

1) Take two nylon rectangles and stitch them together across the top. I think I used 1/2" seam. I did NOT backtack at the beginning and end of the seam to seal it; I was going to rip it out later.

2) I sewed the two seam end bits to the main body of the case--I could probably have just pinned them but pins scare me. (I have a tile floor that makes it hard to find pins when I drop them, I have curious dogs, and I have shaky hands. Terrible combination.)

3) I put the middle of the zipper on the line of stitching holding the two nylon pieces together. I stitched it down on the left and right.

4) I used a seam ripper to take out the line of stitching under the zipper, and had two rectangles held together by a zipper.

5) Then, because I am paranoid, I used a zig-zag to stitch it down AGAIN. (Shown: one side with zig-zag, then I also did the other side.)

I just want to reiterate, here, that this is for a HORSE, and visible or uneven stitching doesn't matter. I won't win any awards for my craftsmanship, but hey, it's a horse.

Step 5: Making the Cases: Outside Layer

I took the insulating material and folded over one short end, and stitched it down. Again, for this, I could probably have used pins and skipped a line of stitching, but pins are scary. So.

I am putting one case on each shoulder. When it's on, I want the zipper to be in the back, and I want the zipper tab to be at the bottom when it is closed. So I waved the rectangles around this way and that way until I figured out which side was the outside on each one.

I stitched the insulating material with the folded-over bit next to the zipper, onto the outside of the case.

(Ideally, all the pieces would be the same size. I made a slight miscalculation and didn't have quiiiiite enough material for that. It did work out but I suggest having enough material on hand.)

Step 6: Making the Cases: Tabs for the Elastic Straps and Stitching Around the Edges

Making the tabs:
I took each of the 8 7" by 3 1/2" rectangles, folded it so it was 3 1/2" by 3 1/2", and stitched the ends together to make a tube. I used a zigzag stitch hoping that might help prevent fraying.

Positioning the tabs:
I determined what was the front, side, and bottom of each case. I put a tab on top of the outside of the insulating material: at both corners of the top (oriented vertically), the lower corner of the front (oriented horizontally), and at the back corner of the bottom (oriented vertically). These will, of course, be different corners for the left and for the right.

The tab should be facing INTO the center of the case; when the outside edges are stitched and the case is turned inside-out, they will be facing outwards.

Closing the case:
I stitched all the way around the three closed edges.

I started by zipping up the open side, so that the zipper would meet well once it was done. Then I put "right sides together" (the outside of the bottom of the case was touching the outside of the insulating material, with the tabs sandwiched between).

Then I stitched a line down each long edge.

I test-fit the ice pack, since I wasn't sure that an inch of seam-allowance-etc was going to work. It looked fine.

So I then stitched the bottom closed.

Again, because I am paranoid, I went back around with a zig-zag stitch to improve durability and hopefully prevent fraying.

With that done, I turned the whole thing right-side out.

This is, of course, repeated in mirror-image for the other case.

Step 7: Adding the Elastic Straps and the Buckle

Elastic straps:
The elastic straps were easy enough. Stitch each strap in its correct place on one case, then to the matching tab on the other case:

Top back tab to top back tab
Top front tab to top front tab
Chest tab (bottom front) to chest tab

Put "right sides to right sides"--that is, don't just overlap the material. Stitch it together, then open the material up. Now stitch the leftover edges down to the tab. Here again I used a zigzag stitch trying to get durability etc etc.

Buckle strap:
The buckle will go around the belly. One strap attaches to the belly strap; then half the buckle goes on the end of the strap. The other tab attaches to the buckle.

You can see that I had to reduce the diameter of the strap to put in the buckle. All I did was start with 3" material, then fold over the corners to make it 2", then wrap it around the bar at the end of the side-release buckle.

Using the ice vest:
To put it on the horse, unzip each zipper and insert an ice pack in each case (and close the zipper). Put the whole thing over the horse's head, position on the shoulders, and then pass the belly strap under and buckle it in place.

Click "next" to see what I did when it didn't fit.

Step 8: Adjusting the Fit

Okay, well, I have a degree in physics...that means that we don't let me near any math with actual numbers in it. I somehow managed to screw up the length of the straps, which was irritating, but not wholly unexpected. I measured 20", 20", 36", and 36"; I decided to use 18", 18", 34" and 34", taking into account the length of the tabs as well. I apparently screwed up royally, as the thing was very loose on her.

Considering I attached these things down VERY firmly, with two seams per tab, it would have been hard to rip the seam and start over. And besides, I don't really want to cut that elastic; maybe someday I'll want it longer, or something. So I folded the straps back over and tacked them in place, taking out a few inches on each strap (6 inches on the belly strap). I left the folded flap loose while I checked the fit again. Once I was sure the fit was right, I put in another seam to keep that flap from, well, flapping around.