But Elizabeth Brian of Temecula says those things can pose a deadly danger in the form of carbon monoxide (CO) poisoning. She knows this because she and her family nearly lost their lives.
"It's a terrifying experience for my entire family literally being poisoned and almost dying from CO poisoning," Brian said.
Capt. Bret Cerini of the Riverside Fire Department says this time of year is the worst for carbon monoxide poisoning.
"Houses are closed up so they're not ventilated," Cerini said.
Brian says there are multiple sources of CO in homes, some we don't always think about, like the fire place, for example.
"Especially in the winter, the fireplace can get clogged," she said. "You're running it a lot."
Another source of CO is the water heater, even if it's in the garage.
Carbon monoxide poisoning is preventable with the use of a carbon monoxide detector. In fact, in the state of California, it's the law that nearly every home have one.
"It can be a standalone carbon monoxide detector or it can be a combination carbon monoxide-smoke detector, but all homes have to have carbon monoxide detectors," Cerini said.
There are several types of carbon monoxide detectors in the market and they range in price from $15 to $80.
There's one that simply plugs in anywhere you need it and it has a digital read out. Another one is a carbon monoxide-smoke detector that can link up to other carbon monoxide smoke detectors, so they all go off at once.