"The energy drink issue is one that has come up repeatedly when talking about hydration and maintaining the health of our firefighters," said Gainesville Fire Rescue Captain Michael Heeder.

Energy drinks are full of carbohydrates, sugar, and caffeine. Too much of these ingredients make energy drinks function like a diuretic, not a stimulant.

"As a diuretic, it makes the person prone to dehydration," said UF Pharmacy Professor Paul Doering. "Dehydration of course is the sum of all the liquids that are going into your body and the liquids going out of the body. So a person's fluid status is determined by a whole lot of things."

And that's why Gainesville firefighters have been told to rehydrate with water, not energy drinks.

So whether firefighters are inside of burning buildings or rescuing people under the hot sun, they're now drinking water, not energy drinks, to rehydrate.

"It's always good to drink water first," said Heeder. "Go ahead and replenish your body's fluids then after about an hour or so, then you can start worrying about replacing the electrolytes and the salts and the minerals that you find in these energy drinks."

Heeder says the firefighters are reminded of this all the time, and it's even included in the department's written procedures for dealing with heat-related risks.