Published: Nov 06, 2010 1:48 AM EDT
Updated: Nov 05, 2010 10:49 PM EDT

CAPE CORAL, Fla. - When the temperature dips you may run to the thermostat. But experts we talked to say your central air may not be ready and waiting to warm you up.

When you switch from "cool" air conditioning to "heat" you may experience a foul smell from emanating from your vents. Some are concerned enough to call 911 thinking the system is on fire. Firefighters will tell you they get an increase in "false alarm" calls when folks start using their heat after a long summer.

Experts tell WINK NEWS, debris builds up on the heating elements over the summer and when you flick the switch for the heater to come on that debris burns. Fire officials say it should only last a few minutes.

If the smell continues or if you see smoke call 911. If you use space heaters to stay warm, experts recommend they be kept at least 3 feet from any combustible object.