Well no more, this instructable is quick and easy and can be made in advance.
Step 1: Supplies
3.Plastic bread bag
6.Hair dryer (optional)
Step 2: Step 1
2.Then take it off your head and fold it over so there is a lip about the size of your ear.
3. Take the mighty duct tape roll and seal off that ear size pocket except for about 3 inches that you will leave open.
4. now take the calcium chloride and put about 2 or 3 table spoons into that 3 inch gap.
there is a chemical reaction between the calcium chloride and the water that'll make it heat up. Don't worry, it doesn't create a gas
Merry Christmas and Happy instructing!
(This is my first instructable, so if please leave any comments that you have)