Take the contents of an MRE heater and put in an empty plastic soda bottle, add some water, seal cap and lay it down and back off many feet and wait. Part of the heat generation causes the gases to expand and will blow the bottle up. 
Not that I would know. 
Went through C-rations and MRE's when I was in, different MRE than back then now. With C-rats, I used to keep some under the heater ducts of my helicopter so I always had a hot meal. With MREs during desert storm we used to get together and collect select packets to make some type of casserole for dinner. Had some interesting combos but always was better than plain MRE's, especially sharing. Used to mix them with Ramen noodles too and used unsharpened pencils as chopsticks. Married to an Asian you learn to use chopsticks. I think the kids could use chopsticks before they could use a fork.
