In my last post I actually did mean hypothermia (cold weather injury) rather than hyperthermia (heat stroke). Surviving 90 degree heat with adequate water (the soldier reportedly had a camelbak and 2 canteens, about 4-5 litres, this would have been more than sufficient) is easier than surviving 32 degree cold (could it have rained during the night) during the night time without adequate clothing and shelter protection or the skills and ability to light a fire. But if the soldier had suffered heat stroke then most likely he would have died on the same day within hours of the navigation exercise finishing before the cooler temperatures of the evening. But I would have found this unlikely simply because 4-5 litres of water would have been sufficient to make it through until the cooling evening temperatures. He could of then walked the 3-4 miles home during the cooler evening temperatures if he knew how to use a map and compass with very little water. If this soldier had not died because of an unrelated medical condition this is certainly a most bizarre tragedy.