Heat-related football deaths tripled between 1994 and 2009, according to a new study by University of Georgia researchers.

They scientists are not sure why high school and college players became more susceptible to fatal heat injury, but they suspect higher morning temperatures may play an important role.

The researchers also found that Georgia had more heat-related deaths than any other state, with six.

The scientists studied the trend by building a detailed database including the temperature, humidity and time of day, along with the height, weight and position of each of the 58 players who died of hyperthermia during the study period.

The morning heat index was consistently higher during the second half of the 30-year study period, when most of the deaths occurred, they found.

"In general, on days the deaths occurred, the temperature was hotter and the air more humid than normal local conditions," said UGA climatologist Andrew Grundstein, the study's senior author.

Grundstein, a geography professor, and his co-authors found that most deaths occurred in August, when practice often is the most intense, and more than half the players were struck down on days when practices ended before noon.

Grundstein also found that linemen are most susceptible to overheating. Of those who died, 86 percent were linemen.

But the study also revealed that football players have grown larger over the past three decades.

Grundstein now is working with UGA kinesiology professor Mike Ferrara on a study of heat-related injuries in Georgia and how more deaths might be prevented.

Heat-related deaths are highly preventable, Grundstein said.

Grundstein's co-authors on the national heat death study, published in the International Journal of Biometeorology, are geography professor John Knox and graduate students Craig Ramseyer, Fang Zhao, Jordan L. Pesses, Pete Akers, Aneela Qureshi, Laura Becker and Myron Petro, all of UGA.

--Reprinted with permission of OnlineAthens/The Athens Banner-Herald