A work colleague had a similar experience back in the very hot marathon of about 1980 or so. Temps were in the 90s. He had a good run until he woke up in the medical tent looking up at his wife with an IV in his arm. Not sure if he did any more marathons after that.
Hope Ari is heals well. Scary story.
We had a Swede (Anders) staying with us this year, to run the marathon; he said that despite the seemingly not super hot temperature generally, the sun was bearing down on them the whole time, and that was the problem.
Looking forward to seeing Ari, hopefully at a CSU park-O soon.
Yay for Anders! Go OK Linné. Swedes are not used to sun in April yet. At the end of September is when they have remembered what a "sun" is :)