On a related note:
It's not a bad idea when you get a new bike (or at least, new to you) that you just figure on changing all the fluids. Brake, clutch, coolant, oil, final drive. Unless you really know the owner of the bike pretty well, you don't really know how long it's been since any of those were done. If you do them all yourself (or have them done), then you'll have a starting point for any future changes, and you'll always know how old your brake fluid etc actually is.
I ride year round, and it can get into the low 20's-high teens here in NC in the winter. If I'm sitting still for too long, eventually the fan is still going to come on. The real warning sign is if the fan is on and the temperature is still climbing past 220; then you have some sort of issue.
I have a radiator flush/coolant change guide that I made, and follow it when I do the coolant changes. I can send it to you if you want. I contains info both from the service manual and from a post that 2daMax made on this forum that has some really nice photos of the procedure.