I usually put little toys in caches as swag, but I was mentioning to a friend that I had started picking up mini first aid kits and wanted to get a couple of cheap orange vests (it is hunting season after all) to leave. He suggested getting the little handwarmers that hunters sometimes bring with them (the ones that you squeeze to activate). I had thought of it too, but I wasn't sure how they would hold up in extreme temperatures. I'm afraid they would either break or no longer activate. Does anyone know? If they would hold up, I would think that might be a nice thing to find if you are getting a bit chilly hunting. Thanks.