Category Archives: Self-heating Meals

Is the heater affected by altitude?

No! In October 1997, a climber from Vancouver, British Columbia activated the heater at 25,350 feet on Mount Everest. He was delighted to note that it was not affected by the elements. As you are aware, it is extremely difficult to light a fire or stove at high altitudes because oxygen is required. This is not so for the heater. Sadly, the team had to return to base camp because the weather was ferocious. No one made it to the top!

The meal did not seem to get really hot after 12 minutes. Why?

Make sure the heater is placed UNDER the meal before activating with water. If the heater is on top of the meal, the water will not make contact with the heater and therefore no heat will be generated. Equally, if during meal insertion, the heater has been bunched up at the bottom of the sleeve, it will not work as efficiently. MAKE SURE THE HEATER STAYS FLAT UNDER THE WHOLE MEAL. It is also possible that the heater and meal inside the sleeve were not kept reasonably flat initially (first 30 seconds). The heater needs to absorb the water through each membrane and heater element to obtain maximum efficiency.

How much hydrogen is given off?

A trace amount mixed with steam. An hypothetical situation: “There are 15 men inside the cabin of a fire truck. It is winter and the doors are shut to keep in the heat. How many heaters can be activated at one time?  Make sure there is plenty of ventilation. By doing this, there is no problem in activating 15 meals (one for each of the men). Always activate the heaters in a ventilated area.

Can the heaters be affected by humidity in a room?

No. The heaters are in a sealed sleeve. However, the heater sleeves should be kept away from any contact with water. If the sleeve is damaged then you must activate the heater with water and dispose of the heater/heater sleeve. Care must be taken because of the steam and heat being generated when the heater is activated. If you open the heater sleeve and decide not to use it immediately, humidity can get in and the heater might not function to its full capacity. It is considered inadvisable to open the sealed sleeve and not use it immediately.