Adults 65 and over, along with children four and under are most at risk.
One group you may not think to be at risk in the heat is high school athletes.
Now a new film, '108 degrees: Critical Response' describes the dangers of heat-related illnesses during exercise.
The film is a production of the Arkansas Educational Television Network (AETN) and shares the personal stories of two Arkansas families whose sons died after suffering a heat-stroke during football practice at high school.
"Will went down at practice," says Patti James. "Will was light-headed, he was having double vision."
"I didn't know if my son would survive the night.," says mother Rhonda Fincher.
Filming happened at several places, including Rogers and Heritage High Schools.
Parents Mark and Tina Davenport, along with Rhonda Fincher, are also featured in the film.
They lost their sons to heat-related illnesses.
The film airs July 21st at 7:00 p.m. on AETN (PBS).