I've looked at these several times but not bought yet. They are intended to keep ice out of rain gutters or at least to keep water from backing up into roof. Ones I looked at put out 5 watts per ft and I think have a thermostat. Should be fully weather proof as they stay in water yr around.

They could be wrapped around pots or put under any kind of outdoor shelter.

Anyone using them?

Very interesting concept. We used heat tapes wrapped around our water pipes during the coldest part winter when I lived in NH. Brrrrrrrrrrrrrrrrr......

Good idea.

This is an interesting idea.   I was introduced to figs by a guy in southern Pennsylvania who trimmed his trees back so that the trunk could be easily wrapped.    He ran some heat tape up the trunk of his well wrapped trees and only turned it on during the coldest nights.

I live near Kansas City (zone 5) and put a wooden box around my very first fig (lots of effort and will not do that again).   I trimmed it up and put a 4' tall 2' wide box around it with some fiberglass insulation.   I ran an extension cord out to the box with a 15 watt bulb inside.   When it got down to 8 deg or lower, I plugged it in for the night.   I never had any freeze damage.

The heating cable seems to come in long lengths and am not sure if they could be adjusted.  Shorter heat tape might work but it all depends on how cold it gets where you live, how well you wrapped the tree and how well your wrapping is integrated into the ground.

Byron (Ingevald)

This could be a simple way to provide heat to the dormant overwintering fig trees if it works.

I just bought a gutter de-icing kit ADKS 150 (27') .
I was going to use for a corner of my roof that is  prone to icing.   You need a grounded receptacle very close since it only has 6' cord.  You also have to be careful not to cross the heating cable.  

The cable is warm to the touch. It puts out 5 watts per foot. 
I don't know if it will put out enough heat to make a difference for a room full of fig trees.
 

Pino:

125 watts won't do much for a room full of figs unless very well insulated. But the cable should have advantages over many other heat sources. It's weather proof and not all concentrated in one spot like an electric heater or light bulb. They come commonly in lengths up to 200 ft.

Thanks for the tip about not crossing the cables. I guess that could cause over heating and burn thru the insulation.