While cleaning out my SUV yesterday, I came across some chemical hand-warmers with a 2008 "validity" date. So I opened them up to see how they'd work. To my surprise, they got very warm.

I suspect it took them longer to warm up than fresh warmers and they probably did not last as long (I was busy cleaning the car and didn't time them). But if you were cold, these would be welcome relief for your hands or feet for awhile.