UK-based Trekmates offers a unique way to cook in the outdoors. Its Flamless Cook System eliminates the need to carry a stove or fuel canister and cooks your meals without fire. As such, it doesn't release any dangerous gas and can be used inside a tent.
The Trekmates system uses a chemical heating packet in place of a traditional fire. Place the packet in the plastic tray portion of the cooking flask or tin, and it begins heating when you add water. The food goes into the stainless steel bowl or cup, which fits atop the plastic heat tray. A lid locks the heat in. Within 7 to 10 minutes, you'll have a hot meal or beverage. The most powerful Super Power Heatpack reaches its maximum temperature of 90° C (194° F) in 15 minutes, providing 15 minutes of cook time at that temperature before cooling down.
A main advantage of the Flameless Cook System is being able to cook inside your tent. Due to the risk of fire and poisonous gas, you can't use the average camping stove inside the tent, meaning you have to cook outside even if it's cold, rainy or windy. Of course, depending upon location, cooking in your tent may not be a wise idea anyway because of bears and other animals.
Magnesium-based flameless ration heaters, which are similar, if not identical, to the heat packet Trekmates uses in its system, have been used by the US military for decades and are also available to consumers. Though the Trekmates system with its sturdy containers is a bit better integrated than some of the older, more basic flameless systems, it's not really the "revolution" that Trekmates claims.
It may not be as technologically-advanced as the Heatstick, but the Trekmates system is much cheaper. You can purchase a pack of five or seven heat packs for £10 (about US$15). Buyers can also select the 850-ml (30-fluid ounce) Cook Box for £30 ($45) or 360-ml (12.7-fluid ounce) Cook Flask for £20 ($30), both of which come with several heat packs.