For those who think the macho mentality in college football can be dangerous to a player's well-being, listen to American Football Coaches Association executive director Grant Teaff, who played the sport in the 1950s at McMurry College in Texas.

"When we played, you worked for four hours straight -- and if you even thought of a drink of water, you were less than a man," Teaff recalls. "That was the psychology. And I have no idea how we made it."

	Bobby Bowden and FSU were devastated by the death of Devaughn Darling, who died during an offseason workout last year.

College football's elder statesmen, Joe Paterno and Bobby Bowden, say they can't figure it out either. They don't understand how the workouts that they did some 30 years ago with little trouble can kill a player today.

"These are just different times," Bowden said last year, following the death of Seminole sophomore DeVaughn Darling after a voluntary offseason workout.

For one, there is the relative uncertainty that comes with many of the over-the-counter supplements players use today to increase performance. In the most recent survey of drug use, 40 percent of college athletes admitted to using nutritional supplements, up from 33 percent in 1997.

Northwestern safety Rashidi Wheeler, who collapsed and died during a voluntary offseason workout last summer, reportedly had two over-the-counter supplements, Xenadrine and Ultimate Punch, in his system when he died. Both contain ephedrine, a stimulant banned by both the and NFL.

An article published Friday in the medical journal "Neurosurgery" became the first to link the dietary supplements with heatstroke deaths in college football. In it, researchers claim both ephedrine and creatine could hinder the body's ability to remain hydrated during strenuous physical activity.

According to the National Center for Catastrophic Sports Injuries, the number of heat-related deaths in all levels of football has risen from 13 in the 1980s to 15 in the 1990s and seven in the past two years alone.

"Athletes, coaches trainers and team physicians should be vigilant in looking for the signs of heat stress," said Dr. Julian Bailes, the chair of neurosurgery at West Virginia University and the co-author of the article. "We have to put more effort into letting players know that there are well-recognized risks in using unregulated diet supplements."

Another factor contributing to the rise in heat-related deaths is the lack of acclimatization in our society. As abstract as it may sound, people have become more reliant on air conditioning and less acclimated to extreme heat. Gone for many people are the endless summer weeks of working on a farm or playing baseball.

Instead, people tend to venture outside for short periods at a time, says Dr. Douglas Casa, which contributes to being less acclimated to the heat.

"Let's face it, if somebody spends an hour outside in the heat of summer, that's unusual," said Casa, a kinesiology professor at the University of Connecticut and the chair for the National Athletic Trainers Association's position statement on heat illness. "Even if guys workout a lot, it's in an air-conditioned facility. We live full time in air-conditioned environments. And when guys go out for summer workouts or two-a-days, their bodies just aren't used to it."

The third contributing factor to the rise in heat-related deaths, Casa says, is the increased size of today's college football players. When an offensive lineman increases his weight to 300 pounds, his body generates more heat, complicating its ability to maintain a core temperature.

"Today's athletes are much, much larger," Casa said. "And when you combine that with the amount and variety of all these untested supplements and the fact that these guys aren't used to the heat and everyone wants that overnight advantage, it's no wonder we're having these problems."

Wayne Drehs is a staff writer for ESPN.com. He can be reached at wayne.drehs@espn.com.