Flameless ration heaters have been used to heat US military MRE rations for decades. More recently, they've been gaining popularity in the outdoor consumer market. These heaters use chemical-based heating as a quick, simple, portable solution for cooking prepackaged meals. The new Mealspec Heater bag jolts this style of cooking system to life with enough heat to boil an egg and cook raw fish.
The typical flameless ration heater has enough power to heat a pre-cooked "meal ready to eat" (MRE) 100 degrees over the ambient temperature within 10 minutes. Typical heaters, such as the Trekmates flameless outdoor cooker, quit rising in cooking temperature well before they reach 200º F (93º C). These flameless heaters are effective at their objective of heating up MREs, but they're not meant to do any actual cooking.
Mealspec calls its Heater bag the highest performing, most reliable flameless meal heater on the market. A spec comparison with other available systems shows that it's not exaggerating, assuming the bag works as well as advertised.
After Mealspec's heating packet has been placed in the bag and water added, the ensuing chemical reaction heats the water just above the boiling point to 220º F (104º C) in just 12 seconds, cooking at above 180º F (82º C) for 12 minutes. Not only can that heat a prepackaged meal, it can do light cooking, including hard-boiling an egg and cooking fish filets. Cooking times will vary based on what's being prepared. Mealspec warns that the leftover water cannot be used for drinking and food needs to be stored in its own container when cooking in the Heater bag.
Mealspec announced the new Heater bag earlier this month. The bags are available from the company's website, starting at US$18 for 12.