US MRE meals come with a heater.

You take the MRE heater, (looks like a big bag.) open up the bag, and add a bit of water- (ounce or 2) The MRE is added into the bag for heating.


For Coffee-- there is a hot beverage bag. Add the instant coffee to the hot beverage bag. Seal. Place inside MRE heater bag.

When hot, pull out, pour in to cup (kinda hard to drink from bag)

MRE heaters could be used for heating many things that need warming, but not true boiling (about 100 degrees above ambient- 200F ish)