I suppose a quick check of the autopsy results would sort this ? They either found poison or they didn't. It would seem odd that they would say it was because of a snake bite just because they ruled out dehydration and heat exhaustion?
It would appear that someone's been a bit hasty in jumping to a convenient conclusion. Presumably these tests are as much a test of survival and endurance as they are map reading so a great deal of attention would have been paid to the prevailing weather conditions.
I've never known the DS on any military exercise not fully brief participants on the climatic conditions and ensure that they have sufficient protection and solids/fluids to meet expected conditions.
It is not, in itself, unreasonable to expect soldiers to operate in extreme conditions and proper precautions are usually taken by the DS who will ensure that each participant, at least sets out with, adequate means to maintain hydration. If someone empties their water bottles to lose weight then they really haven't learned what being a soldier is all about. That is not what you'd expect at the end of such a long and arduous course, that trains soldiers to the highest levels of effectiveness and self-discipline.
The stripping off of gear and disorientation does sound like heat exhaustion is a possibility but there is another possibility which is the exact opposite. I don't know the local climate so have no idea if my theory holds any water. If night had fallen it could be that there was a significant temperature drop. If a clothed soldier, who has been pushing himself to the extent he is bathed in sweat and his clothes soaked, doesn't take stock of himself and change into dry clothing then hypothermia becomes a real possibility. As I say, you'd have to know the local climate to know if that's a possibility. I once had to treat a soldier who was hypothermic in Kenya, because he was found in the early morning it was assumed to be heat exhaustion so he was soaked and then flown on an open helicopter pod to my location, it was a very close run thing.
Apologies, I digress. It is important, for the US Military as well as for the family, that the correct reason for this death is found. Anything that may help prevent future casualties is important as is knowing that sometimes things go wrong, no matter how good the preparation.
Avg temps then at night were around 21-22 C. My own feeling is that if they are adequately briefed and presumably already fit, then the conditions need to be as hard as possible as long as there is some reasonable provision made for emergencies as there appears to have been. I do not think we should be so risk averse as to undermine the very thing we are trying to achieve and that goes double in the arena of special forces.
An Autposy besides showing snake bite would presumably show venom in the Pvt's bloodstream. IIRC my "Dont Play with the Wildlife Briefings" Water Moccasins Venom os also Corrosive to human tissue like a Rattlers is. An Instructor at JOTC in Panamas Jungle School got his finger slightly nicked by a Fer de Lance while showing us and lost the finger several days later.
Ref' comments about temperature - the heat will have undoubtably made an effect on the bloke, but the humidity is the real danger. His sweat won't be working as effectively as it should, and thus the subsequent loss of body salts etc could contribute drastically to his decline. I've seen mega fit blokes, clued up to ****, deterioate and go down in the space of 30 min thanks to high temp and high humidity. It's a bastard!