HARRIS COUNTY, Texas -

Firefighters dealt with the extreme heat while battling a massive blaze at an apartment complex in north Harris County.

It was a 2-alarm fire Tuesday afternoon that quickly burned out of control. Several units of the Citation North Apartments located in the 400 block of Highland Cross were gutted as firefighters did their best to stop the flames from spreading.

"Three units damaged by fire, six or seven damaged by water or smoke," said Assistant Chief Tony Spitzenberger.

But it wasn't just the flames that were a problem for the firefighters. Rising temperatures and a relentless heat index also took a toll on some of them.

"With the heat index being above 100 and these guys being encapsulated in suits, it's extremely difficult to dissipate the heat so we have to rotate them more frequently and let them get out to cool off," said Ponderosa.

Firefighters did their best to stay hydrated, drinking a large amount of water and sports drinks. They also took breaks when possible. But the heat was also a problem for residents like Alex Marquez, who lost everything in the fire and was forced to stand outside.

He used his cowboy hat to fan and try to keep his 9-month-old son cool in the intense heat.

"My baby had a cowboy hat on. I was covering the sun. I was so worried; that's why I came so fast to take care of my family," Marquez said.

Officials are investigating the fire's cause. No word if there were any injuries. 

>>Click here to see more photos. ,