"You might go on a simple vegetation fire and next thing you know, tires are on fire, couches are on fire, drug waste," said Captain John Gaddis, Cal Fire Butte County.
It's no secret that firefighters have a dangerous job.
After the last month's deadly California wildfires, researchers are using blood and urine sample from 200 firefighters to study just how harmful smoke exposure can be.
And there's no way to predict just what'll be in that smoke.
"It went from organic material to structure fire, you have thousands of homes then up in flames as opposed to one structure fire. You are exposed to all that smoke," said Gaddis.
There are some health care procedures in place.
"If you come across something, whether it's smoke or blood born, it's put in a computer database, and they maintain that database right up until you retire," said Gaddis.
"Our unions are always trying to fight for us to get better protection for exposures," said Captain Joe Chavez, Cal Fire Butte County.
But with synthetic material in nearly all home furnishings, the danger's only getting worse.
"The fuel load inside the homes now are basically one or two molecules away from being gasoline," said Chavez.
While firefighters in California have state-of-the-art protective equipment, this gear can only go so far.
"You're still absorbing that through your skin, your body does absorb those chemicals, you're not in a bubble," said Chavez. "Over 60 percent of firefighters get cancer."
Even knowing this, firefighters I spoke with say, they have no regrets.
"You never know what you're going to get, never know when the alarm's going to off but at the end of the day you go home happy with the work you did," said Cody Sheets, Cal Fire Firefighter 1.
"Being able to serve the community and do what I love everyday, is so rewarding. I think that the inherent danger is totally worth it, someone's got to do it and it might as well be us," said Jessica Ellis, Butte County Cal Fire Firefighter 1.