works great. I wont be able to speak to the quality of the bag, since this will likely only be for emergency use, but Ill provide some data with respect to heating. I filled it with around 3 gallons of cold tap water (checked with a food thermometer / 55.5 degrees) and laid it direct sunlight (Denver, CO / December 9th) at 11am. Outside air temperature was 60 degrees. By 1 pm the temperature reading on the bag was just barely starting to illuminate the 92 degree mark (outside air temp had warmed to about 64 degrees). By 2pm (air temperature was 66 degrees), the water temp was registering a solid 92 degrees. By 2:30pm (outside air temp still at 66), the 98 degree mark was fully illuminated. From there the water temp started to decline as the strength of the sun declined (sunset today was 4:35pm).
Heats well
works great. I wont be able to speak to the quality of the bag, since this will likely only be for emergency use, but Ill provide some data with respect to heating. I filled it with around 3 gallons of cold tap water (checked with a food thermometer / 55.5 degrees) and laid it direct sunlight (Denver, CO / December 9th) at 11am. Outside air temperature was 60 degrees. By 1 pm the temperature reading on the bag was just barely starting to illuminate the 92 degree mark (outside air temp had warmed to about 64 degrees). By 2pm (air temperature was 66 degrees), the water temp was registering a solid 92 degrees. By 2:30pm (outside air temp still at 66), the 98 degree mark was fully illuminated. From there the water temp started to decline as the strength of the sun declined (sunset today was 4:35pm).