They face two very big problems they faced - flames spreading throughout the building and the high heat and humidity.
Firefighters can't shed 90 pounds of equipment fast enough to catch their breath and cool down.
"Make sure the guys are rehabbed. We change out our guys frequently. That why we brought in so many towns to help us," Barry Turner said.
The fast-moving fire began around 11:45 a.m. in the upper floor or attic area of the three story condominium that is part of the Brittany Chase complex on Brittany Drive off of Berdan Avenue.
"Police came and knocked on the door hard just to say 'Come on! Come on! Get out!" said medina cajevic, who helped a 90 year old resident escape.
Others too were running from the building.
"I just saw everyone like rush out, everyone started crying," Priyal Shah said.
As everyone got out safely, some were still praying as the fire quickly spread.
"There is a common attic area in the building and once it took it up there , it went through the building," Turner said.
While this fire was most fought from outside, the heat forced dozens of firefighters to rotate out at various times, pulled into the shade and given water.
Others were brought to cooled rehab tents where they could be evaluated.
"Get them hydrated. Get them fluids. Make sure their heart rates are good. You want to do that throughout the event," Dr. James Pruden of St. Joseph's Health Care System said.
One firefighter fell through a portion of a floor, but returned to duty. Five other firefighters were treated for heat exhaustion.
As many as 20 units were damaged by the fire.