PALM BEACH COUNTY, Fla. — We know it's hot outside, but imagine wearing about 100 pounds of gear and racing into even more extreme conditions.

That's what firefighters do every day, and they can't go inside to escape the heat.

Safety in this heat is really a top priority for Palm Beach County Fire Rescue. Firefighters tell WPTV that means a lot of water before they even arrive at work.

The sun beating down and the black flag flying overhead. That means it's the most extreme conditions for Palm Beach County Fire Rescue training.

"In an hour's time, we can’t get a lot of work done with just one single crew," said Justin Schainuck, the division chief of training and safety for Palm Beach County Fire Rescue.

It's Chief Schainuck's job to make sure everyone stays safe.

With a black flag, firefighters can only do 10 minutes of heavy work with 50 minutes of rehab.

"Unless you are a firefighter or have been put in those conditions, you can’t put it into words," Schainuck said.

WPTV caught up Thursday with Capt. Adam Perricone, moments after he came out of the agency's burn building and headed to rehab..

"Tired but I feel good. We did a good job," Perricone said.

Rehab involves checking vitals like temperature and blood pressure, along with misting fans and cooling chairs.

"It's good to get your body temperature down. This gear doesn't breathe," Perricone said.

After nine years as a firefighter, Perricone knows what he needs to make it through the job.

"The more you train in gear, the more comfortable you get with being hot. And the better shape you get into, the longer you can stand it," Perricone said. "The better you hydrate, the better you feel while you are working. It doesn't change how hot it is, but it changes how well you can tolerate it."

When you factor in the jacket, gear, and tools, it's an extra 100 pounds firefighters are taking into the most extreme conditions.

"Once you are thirsty, it’s too late. So we always preach to the firefighters, you start hydration the night before you come on shift," Schainuck said.

And this training helps these first responders prepare for the real thing, summertime or not.

"Sometimes our gear melts. The helmets, we have stickers on them that melt off all the time," Schainuck said.

"Hydrate before. I gotta get good sleep when I can. And be trained and proficient in what I do so everybody goes home, and hopefully we can make a difference inside the building," Perricone said.

If a firefighter's vital signs are not within a target range within 20 minutes of coming out of that fire or training, they are taken to the hospital for evaluation.