Sprinkle Cayenne pepper into the socks or down into the fingers of your gloves. I don't recommend this for mittens.
Step2
Put them on! That's it. Your body and the pepper will do the rest.
Tips & Warnings
The thermogenic reaction of your hands and feet to the pepper is what generates the heat. It is a great way to add a little extra warmth when you know you're going to be exposed to the cold for a little while.
Do not use if you have any allergy to peppers of any type.