Experts say that wildfires can be doubly dangerous for firefighters; when homes and forest burn simultaneously, both heat and smoke conspire to make air unbreathable.

Below are a few of the risks wildfire firefighters like the elite Hotshot crew face in the line of duty:

Heat: In extremely high temperatures and wearing heavy protective gear, firefighters often experience heat stress, which can lead to nausea, light-headedness and weakness.

This can progress into heat strain, which causes both the core body temperature and heart rate to soar.

If there's no relief from the heat, a firefighter can experience heat stroke.

"The problem with wild firefighting is that unlike structure fires where you have a self contained breathing apparatus, in wild firefighting there is no way you will have an air supply that will last long enough to do that," says Lou Paulson, president of California Professional Firefighters.

Toxic Air: Smoke and dust from a wildfire produce a variety of toxic substances and gases like carbon monoxide, sulfur dioxide and formaldehyde.

"You can have folks on the fire line for 72 hours or longer with no break at all. There are long work periods and no rest," he says.

"A filter mask has to be filtered for the particulates that you are dealing with, which you don't know because you are in a wildland environment."

Fatigue: During the initial surge of the fire, the front line is very difficult to control, according to Paulson.

It's not uncommon that firefighters get so exhausted that they succumb to an intense need to nap on the fire line after long hours fighting relentless flames and inhaling toxic gases. Thank you.