(CBS/WIBW) - With high school sports practices getting underway in Kansas Monday, we can expect kids will be practicing for hours in the summer heat.
But playing too hard under the summer sun can lead to heat stroke.
Dr. Robert Gotlin of Beth Israel Medical Center says it's a common problem.
"Heat injuries or dehydration injuries are right up there with ankle sprains," he says.
The heat can cause brian impairment, kidney problems and blood clots.
Last year, 15-year old Max Gilpin died from heatstroke during football practice in Kentucky. Since 1995, at least 29 high school players died from heat related illness.
Part of the problem is that there are no rules on how long or hard teams can practice in the sun. For the first time this year, schools are getting some guidance.
The National Athletic Trainers Association has put out a set of guidelines.
Only one daily practice is recommended during the first week lasting no longer than three hours. In the second week, double practice days can start, but kids need to rest three hours in between. Regular water breaks are a must.
The guidelines aren't mandatory, but experts hope teams adopt them so kids can compete safely.
Experts say thirst, loss of appetite or sluggish behavior are signs something is wrong.