On a related note - one that may seem obvious but apparently isn't - if you're heating the contents of a can, loosen the lid first, and wear cloves or something when handling the can. It will be hot.

If you're some old fart who still has his P-38 GI can opener from Vietnam on his key chain, loosen the lid until there is about 1/2 inch or so left. the lid will serve the same as a lid on a pot, so the contents warm faster. The cans with the pull-top lids need only be lifted up a little bit.

You're unlikely to get a face full of boiling liquid by failing to do so, unless the can is really super-heated, but it is possible.

If you choose to heat the can by immersion in hot water, you need not do this since the can will never get hot enough for the contents to explode out of the can. But you will still want gloves to handle the hot can.

Onward and upward,
airforce