I've often smoked the same pipe several times in a single day. It doesn't take long at all for it to cool sufficiently (without refrigeration).
This is a perpetual topic when pipe smokers gather - smoke it one bowl, stop, long term rest - or smoke it all day, letting it cool down, and running a cleaner or more through between rests. There's no consensus on this, except that, if you don't give a pipe long term rests, it is going to turn foul and nasty, as well as perhaps cracking, with time.
I have a modified system - three pipes a day, one bowl from each, repeat teh next day - after a good cleaning - then long term rest. That seems to be working. (If I want another bowl, I get out one of the pipes that I enjoy but are not a regular part of my rotation - or a cob, which, of course, doesn't need long term rest.)