We now know what killed a 19-year-old University of Maryland football player. Jordan McNair's family said he died in May from heat stroke after a supervised practice.
But how does a young, healthy man die from a heat-related illness?
"Young people and athletes can die in these situations it's because you can just say well, it's really hot out here, I'm just going to push myself, I'm trying to be the best athlete I can be," said Dr. Eric Kiechle of Medstar Union Memorial Hospital.
But doing that can be deadly like it was for McNair, a University of Maryland freshman who died in May.
"We think heat stroke and heat exhaustion those are things that can kill you, we saw that with Jordan McNair," said Dunbar High School JV football coach, Ty Johnson.
Johnson has seen his share of young talent. Talent like McNair He and his team are vigilant when players are in hot weather.
"The kids' safety is at the forefront of everything that we do. We have an organized 8-week program with heat acclimation just to prepare the bodies for heat," Johnson said.
McNair died from heat stroke after an organized practice.
"Heat can be deadly to anybody. Old, young and there's a whole spectrum of heat-related illnesses ranging from just feeling hot and uncomfortable some people get a heat rash," Kiechle said.
Exerting yourself while exercising in the heat can get very serious, very quickly.
"As you get to the more severe end of the spectrum, you have things like heat exhaustion and then finally heat stroke which is the most severe type," said Kiechle.
And without proper hydration and tempering outside time with AC time, it can be deadly.
"Once you develop heat stroke which means that your body temperature is elevated it's almost as though you have a fever, you have a high body temperature and on top of that you also have changes in mental status, confusion, you can pass out, you can be very erratic."
Signs coaches are always looking for.
"We'll come out here and run sprints, we'll run distance but we always keep an eye on them to make sure they're not being overexerted," Johnson said.
A foundation has been created in memory of McNair. The Jordan McNair Foundation was established by his parents.
It is sponsoring a training facility, a scholarship fund, and heat-related illness education.