NEW ORLEANS — The New Orleans Fire Department has good news: The 10 firefighters who were treated for smoke inhalation in Sunday's fire at Le Méridien Hotel are all OK.

But why did so many need medical attention, especially with all their protective breathing gear? And what can you do if you are ever in a fire? 

NOFD officials explained that in a high rise, firefighters are going up multiple stair wells with no electricity, in the pitch dark. They are carrying up to 100 pounds of gear and equipment.

The men don't want to run out of oxygen in their tanks before they find and start fighting the fire, so they wait to attach their masks to the tank when they do reach the fire.

SEE: 10 firefighters hospitalized after battling fire at Le Meridien hotel in New Orleans

But in the dark, they couldn't see the smoke, so they inhaled some when they first encountered it before connecting their masks. 

To understand why smoke inhalation is so dangerous, Eyewitness News turned to Dr. Kyle Happel, a Pulmonologist at LSU Health Sciences Center. 

Happel says there are several reasons. First, it's so hot that it can burn the lips, mouth and throat. The heat can cause your airways to swell and block your breathing. 

Next, there are toxic particles and chemicals in the smoke from things like plastics that are burning. Gasses like cyanide are released and can poison your organs and brain. Today's furniture burns faster and is made with more synthetics. 

Happel said if you are in a fire, crawl on the floor under the smoke that is rising, and try to put a wet towel around your nose and mouth so the dangerous particles get trapped in that makeshift mask.

NOFD officials said once you are outside of a fire, never go back in for any reason. Let them know if some one is still inside, and his or her location.

Families should also pre-plan to have a meeting place away from the fire.