Abilene Regional Hospital Trauma Coordinator Kendal Rutland said heat stroke is a "definite medical emergency."
About 180 people die in the U.S. every year from heat-related illness. Heat actually kills more people every year than floods, hurricanes and tornadoes combined.
Rutland said people who spend a lot of time in the heat should know the signs their body may be overheating.
"You lose the ability to sweat. So dry, hot skin, your core temperature will go over 105 degrees. You can have a throbbing headache, dizziness, muscle cramps," said Rutland.
The elderly and children are most likely to become victims of heat stroke, but it can affect anybody.
Jim Fowler works in his yard no matter the season. He said he takes precautions to avoid heat-related illness.
"I pace myself. Water, sunscreen and I will start early on the weekend and by 2:00 pm I get out of the sunlight for a while. And then it's in the pool and in the shade late in the afternoon," said Fowler.
Rutland said dehydration and heat stroke go hand-in-hand. She said people should start drinking water before they become thirsty and avoid alcoholic beverages.
She also said people who work or play outside should take a lot of breaks and can even put a cool, wet cloth around the back of their neck to help them keep cool.
Fowler said triple-digit heat is nothing new to most Texans.
"It's no surprise to us," said Fowler.