STEVE INSKEEP, host:
On Thursdays, MORNING EDITION reports on your health. And today, we focus on the health of teenagers who'll be on the football field this weekend. Many high school and college teams will be playing in the last of the summer heat, and it is not easy for those players to stay cool. Reporter Deborah Franklin explains why.
DEBORAH FRANKLIN: It's not just the heat or the humidity. It's the uniform. Ernest Lomax is a lineman for DeMatha High School in Hyattsville, Maryland. His team's been running sprints and other drills for a week, but this is their first day practicing in full pads.
Mr. ERNEST LOMAX (Lineman, DeMatha High School): Right now I've got shoulder pads on. I've got t-shirts under this. And I've got sweatpants and a girdle and then my basic underwear. And then I've got my helmet.
FRANKLIN: There's a reason why he's wearing all those layers. Back in 1905, football was nearly banned from college campuses. Eighteen students had died on the field that year, mostly from head injuries and broken necks. That's why helmets came along, and better pads. But that makes players hotter too. And these days heat stress kills at least one or two healthy high school or college football players a season. And it sends a whole lot more to the hospital.
Professor LARRY KENNEY (Pennsylvania State University): It's not uncommon during prolonged, intense exercise for us to be able to measure temperatures in athletes of 103 or 104 degrees Fahrenheit.
FRANKLIN: Larry Kenney's a sports physiologist at Penn State. He says that an 80 degree day with 90 percent humidity may feel safe to the coaches in shorts and a t-shirt, but for the player on the field in full pads it's another matter.
Prof. KENNEY: The equivalent insulation to a typical football uniform is like wearing a wool three-piece men's business suit.
FRANKLIN: Plus, the player's got on a helmet that acts like a toaster. His sweat can't cool him off because it's not evaporating. It's soaking his clothes. And chances are he's still dehydrated from yesterday's practice.
(Soundbite of whistle blowing)
FRANKLIN: Back at the DeMatha High School football practice, the players are breaking for water.
Mr. MCGREGOR: Come on. Let's go.
FRANKLIN: Bill McGregor's been head football coach at the school for 26 years, with 16 conference championships to his credit. He wants to turn these kids into great players, but he also takes heat seriously.
Mr. BILL MCGREGOR (Coach): You talk to them about common sense. You know how you feel. I do not. OK? If you feel you're light-headed, if you feel you need water, OK, go take care of it. Nobody's going to call you a sissy or a chicken or a baby or whatever they used to call you in the old days.
FRANKLIN: McGregor follows NCAA guidelines to get kids acclimated to the heat of August. That means no pads the first week.
Mr. LOMAX: They made us run. Coach wanted to see who has heart, so he ran us all for a good one to two hours just to see who wants to play football, who wants to make his team.
FRANKLIN: Ernest Lomax says he and his teammates push hard.
Mr. LOMAX: We like to wait until they tell us we should stop rather than when we stop on our own.
FRANKLIN: That may be why you ultimately can't count on the kids to put the brakes on, the coach says. He remembers one boy who gave nothing but 100 percent.
Mr. MCGREGOR: Two years in a row we had to call the ambulance the first day of practice and get him to the hospital for dehydration. I should've been smart enough the second year to realize as a football coach you have to know your kids. Now, ever since that happened, we try to identify who's the kid who'll just push himself until he can't stand up.
FRANKLIN: Playing safe doesn't take fancy equipment, but McGregor says it does take more adults on the field during practice, including somebody you can designate as a look-out coach.
Mr. MCGREGOR: Even a parent, you know, just look. You have big eyes. And you know, you can see what's going on. And somebody that doesn't look like he's feeling too good, go over, put your arm around him, and see what's going on.
FRANKLIN: And sometimes you even need somebody to face down the coaches.
Ms. WENDY NORRIS (Trainer): Last year we had a game where the heat was just excruciating, and I wouldn't let them play the game.
FRANKLIN: Wendy Norris is DeMatha High School's lead athletic trainer, and if it's too hot by NCAA guidelines, Norris says no football.
Ms. NORRIS: I just couldn't let them, you know. I had a few grimaces and growls and such from the coaches, but they know it's the right thing to do. And that's what we did.
FRANKLIN: Coach Bill McGregor admits he may grimace sometimes, but he says in the heat of the late summer a trainer like Wendy Norris is the most important person on the field.
For NPR News, I'm Deborah Franklin.
INSKEEP: Keeping hydrated is the key to keeping cool on the field or elsewhere. And you can get tips on how much and what to drink at npr.org/yourhealth.