Too high of a temperature will shorten their lifespan. I would find out what the best temperature is for the fish and keep them there. Usually 25 to 28C is fine,
I have read on here that if you keep your temp water higher it speeds up the metabolism of some fish that aren't used to the hot water. This leads to them having a shorter than normal life.
If i was you i would easy the temp back down slightly. It also helps out with the heating bills!!