I agree with Celle about the warm pool. I think you should hold off for a while. Also it is super easy to overdo in the pool--you don't realize it until later. I had the hot flash/temperature control problem when on pain meds too. Freezing while icing (in the hottest part of summer mind you), then sweating later... You could take your temp but you will likely find it is just the weirdness of tkr recovery.