How to have a lamp turn on when inside temp drops below sixty.
 

I'm a snowbird and worry about a furnace failure while I'm away. I've heard
that there is a temperature sensing switch that will turn on a lamp if the
house gets too cold. I'd like to set a lamp in the front window so my
neighbor can check the place as he drives by without coming inside. Does
such a switch exist? Who sells it? Thanks in advance.