That theory makes sense, thanks, my reason for asking was we have a lot of problems here in our area, which probably doesnt reach those temps, of the frozen ground heaving and in the case, such as an outside frost-proof hydrant, or even conduit coming up thru the ground, being pulled loose or breaking from the buried part.
I can definitely see the sun thawing it out quicker then the surrounding area.

All the really good ideas I've ever had came to me while I was milking a cow.