When a fire is burning inside a home, the chemicals you can't see may be more dangerous than the visible fire and smoke.
South Metro Fire gave 7NEWS a firsthand look at what happens inside a burning building. Our cameras were allowed inside a burn demo, as firefighters searched for potential victims inside.
On Tuesday, two kids were found hiding in a Denver home during a fire and were rushed to the hospital in critical condition.
"Fire will kill you. It doesn't matter who your parents voted for, it doesn't matter what kind of car you drive or what you look like, fire kills, and we forget that because of Hollywood (and) TV shows," said South Metro Fire Community Risk Reduction Specialist Einar Jensen.
Jensen goes to elementary schools and teaches third graders the importance of having an escape plan and getting out of a burning home.
"When you hear that smoke alarm, it's time to get out, just like our kids already do in school. When the fire alarm goes off in school, everybody gets up, they line up, they start making their way out to their school meeting place. We can do it there, why can't we do it at home?" said Jensen.
Inside the burn building, Lieutenants Brad Lingle and John Curtis showed 7NEWS just how bad the visibility can be in a home from their perspective.
"We do these practice training burns in this building and we put fake victims in there, and real furniture, so that we can distinguish between a table, a chair (and) a sofa versus a real person," said Lingle.
They also took monitors inside the building that alerted as soon as deadly chemicals reached dangerous levels.
"It doesn't take a lot of smoke to produce those chemicals that are immediately dangerous to life and health," said Lingle. "Even though there was a small amount of smoke, there were extremely high levels of carbon monoxide and hydrogen cyanide. The fire gases that will kill you are often invisible."
Even if you're in a room far from the fire and smoke, the chemicals that you can't see could be harming you before help can find you. Although, firefighters want you to get out and not hide.
"If you're hiding from that firefighter, you are preventing them from saving you," said Jensen.
However, Jensen doesn't even want you hiding in the first place.
"We need to show two ways out of the house from every room and we need that meeting place," said Jensen. "The meeting place is critical too, because it that means that your family is either out safely, or not, and that when the firefighters arrive, they know if they need to go search in a burning building for people that are hiding or if they can just fight that fire. If you get out to your meeting place quickly, you are saving the people whose job it is to save you."
While we all know that we're supposed to change our smoke detector batteries when we change our clocks twice a year, firefighters want us to know that we need to change our smoke alarm device every 10 years.