The best way to use the Hand Warmers is to not use them. Seriously. Before the next big storm scare that threatens your electric, go to TSK or SYR and get some shipping heat packs.

If you absolutely have to use them, do so very carefully and monitor the temps. Don't put them in a position your snakes can come into contact with them. They can spike up to 163° and no one wants to have a poor baked snake.

Check out the item specifics.
http://www.warmers.com/hothands-extr...rmer-40-count/