Just about every consumable product we buy has an expiration date. from the obvious ones like milk, eggs, and cheese, to the less obvious, but increasingly common ones such as batteries and beer. Yesterday while I was going through my first aid kit to replenish the supplies, I found some hand warmers that expired in 2001. Could these really expire? They have some iron and some other stuff in them when exposed to air heat up to about 100 degrees Fahrenheit for about 6 hours. These weren’t exposed to air and were still completely sealed. I decided to test one, opened it up and in about 20 minutes, the hand warmer was cold. So I guess the expiration date on this particular product actually meant something (maybe it would have lasted another 2 years, but I’m still a few years out).