DALLAS (CBSDFW.COM) – They wear heavy gear and face smoke and flames, but battling the intense summer heat, can be just as tough for firefighters, as the fire itself.

Firefighter Calvin Washington is coming out for a break.  He says, “This 100 plus degree weather isn’t helping the cause, but, it’s what we do.”

Two firefighters were overcome by the heat, and had to go to the hospital after fighting this fire at Standard Waste Management on Cash Road near Irving Boulevard in west Dallas.

After being evaluated, they were sent home from the hospital.

An employee at the recycling facility suffered from smoke inhalation, and was treated on the scene.

Because of the heat, firefighters quickly escalated the incident to four alarms.

They doubled the number of firefighters here to 100 so they could rotate crews.

Captain Janet Cowan has been with Dallas Fire-Rescue for 23 years.  “It’s very hot out here.  You want to get in there and get after it but your body says enough is enough in a lot shorter time than it usually does.”

The fire began when this now charred front-loader somehow tipped over, and ignited piles of recycled and compacted cardboard.

The wind made it more difficult to fight the flames.

Like everyone else on the scene, she relies on volunteers who bring out this truck packed with water, Gatorade, snacks and food.

Cowan says, “It’s just invaluable to the fire department.”