A refurbished unit is just that - a returned unit for any reasons to be cleaned up and getting ready to go.
Whilst some brands/models tend to be warmer than others, it is by no mean that it would fail in the near future. Matter of fact, refurbished units seems to last longer after all the burn-in

You are not gaming and stressing the unit, you will enjoy the comp for a long time to come.
cheers ...