For B&W, room temperature works for both film and prints. For color, ~100F temperature is required for developing film (at least, for C-41 and E-6 films using common developers), but you can use either room temperature or ~100F temperatures for developing prints. To date, I've done all my color prints (a few dozen 8x10s; I'm far from an expert at color) at room temperature (65-70F at the moment). Some print developer kits advertise room temperature use, either as an option or as the primary way of working, but others don't. I believe that even those that don't claim a room temperature option can be used at room temperature with extended development times, but I'm unclear of the details.