FMA,
I would have to say from my experience dealing with guys in the pipe that a 48 hr coma would have most likely been caused by HEAT STROKE. I'm not your Dr., however, and that is obviously their diagnosis so it stands.
Sounds to me like you might have been over training. Mid-day in summer activities can be a bad idea, especially in NC. I've been there for 6 yrs now, not including deployment to where it's much hotter and far more dry, but it's hot! Use some common sense and don't try to be superman. You could die. Hope that's plain enough for you.
Obviously there was some imbalance between your level of activity and nutritional spectrums. Otherwise you would not have gone down so hard.
As you have no medical background, start from the end-state...the incident and coma and work your way backward and see which "building blocks" you can find missing from your routine...too much lifting, not enough rest, not enough high protein foods, working same muscle groups too often, especially lower body, by lifting and a lot of running without enough rest in between?
The article in question listed below mentions "Severe exertion such as marathon running or calisthenics" as a plausible cause to the disorder. I say over training again. Beyond that, good luck with everything. I have no other answers at this time.
I do have a link which describes your issue in detail. As for your physical level of activity, that's up to you and your doc.
I hope things work out for you. Stay safe.
http://www.nlm.nih.gov/medlineplus/e...cle/000473.htm
Hope this helps.
Mick