Is there a leak or no leak?
There is nothing about this condition that by itself suggests a leak.  Common causes are your cold water pipes run near heating ducts or the furnace, or water from your hot water heater expanding back into the cold supply. 

Likewise, a warm spot on your floor could be from ducting, a light below, the sun hitting it through a window, etc.

If there is a leak, sooner or later you will see signs of water - drips, stains on the drywall.  If you do don't see any of these, I wouldn't worry.