DONT..... read the fine print on the back..... IF they dont get shacking up they BURN... I wounldnt trust it. On the back it says dont leave in pockets, I have done this in a packpack and grab it hours later and it was Really hot... I cant remember the brand right now but they have some that are like heater blankets..... why not run a bat powered one? dont think they last 24hrs but idk