Diy if your furnace is not working
 

Yes, it doesn't get very cold in Florida in the winter. But, when it does we still need to turn on our furnace. If you have a gas furnace and your not getting heat this is most likely your problem. There is a small part called a "flame sensor" in your furnace. Most of them are easy to reach and only held in by a small screw.
Just turn off your furnace and remove this sensor. You should first try and clean it. Or you can just replace the part with a new one. The part is very cheap vs paying for a HVAC man to come out to your house to look at it. And of course that is not going to be cheap. Here is just a short video telling you something about this.
DIY Quick Furnace Fix - Flame Sensor - YouTube

This might be good for someone who knows his way around the furnace.

For someone like me might wake up one morning and see a big hole in the ground where our house used to be.

In the old days it was called a thermocouple . You always kept a spare around because they seemed to fail on the coldest days.

Call the furnace guy, giggle...

Yes, that is what they were called. The same goes for inside your gas dryer. People should at least take the cover off the furnace in front and take a look inside if your furnace is not producing any heat. It's just so simple to do and the cost savings is tremendous. Not to mention that "I did it" feeling you get.

"very simple"....
 

as a suggestion to someone who is not mechanically inclined will utter the word "oops!" and cause more cost and danger than calling in a professional.

Never listen to anyone who doesn't volunteer to show you how to do something with the guarantee they'll pay for any extra cost.

"very simple" is often used by those who assume everyone knows what they know and have accomplished what they have.