It’s that time of year again in Southwest Florida. We have to dig to the back of the closet for actual pants, a jacket and even a hat.  

Simply put, it’s cold. With temperatures dipping to the 40s and 50s overnight and into Wednesday morning, many of us will turn off the air conditioning and turn on the heat.  

It’s one of maybe the handful of times we ever have to make the switch, but it’s one that comes with a stinky smell that sometimes can be seriously dangerous.  

When you crank on the heat for the first time in months or even years, your furnace will likely spew out that smokey or even burning smell.  

That’s totally normal.  

But if you’re seeing what you’re smelling, then it’s time to call for help.  

“When the cold comes, people turn on their heater,” said Gordon Durant, owner of Freedom Residential.  

It might be a weird question: But how does their air conditioner actually produce heat?  

ABC7 asked the experts.  

“This is the heater. It warms up. It turns red and the fan blows on it and there we have our heat,” Durant said.  

If that sounds inefficient, you’re right. Running the small heater in your HVAC unit costs twice as much as it does to run your AC.  

It could cost you even more if the heating coils get clogged up.  

“Typically when they turn on their heater, they notice the smell,” Durant said.  

That’s a totally normal situation. But in some cases, and it does happen, dust and other grown on the coils can catch fire.  

“You get dust, microbial growth, fungal growth, bacterial growth,” Durant said. “If smoke comes out of the vents and a dark cloud is going to be an instant big problem. Turn everything off. Turn breakers off.” 

If this happens, you need to call 911 as a fire could be burning inside your air handler.  

“Probably an additional 5-8 calls,” said Amy Bollen, Director of Public Relations with South Trail Fire & Rescue District. “It usually happens in the middle of the night to the early hours.” 

To avoid their firetruck possibly pulling into your driveway, test your furnace before you leave or go to sleep.  

“We want them to burn off that heat or get that funky smell before bedtime,” Bollen said. “If it’s cold enough to turn your heat on, you definitely don’t want to have to evacuate to go outside.” 

While testing your heat, open up a window and turn on some fans to help ventilate the smoke smell out of the home.