That temperature is absolutely fine for the stock cooler and not at all "hot". The only time you should worry is if you ever start hitting past the 70-80s, which would probably be indicative of a dust-clogged cooler that needs cleaning. If you're really worried about the CPU burning out, don't be. Intel chips don't even reach a thermal throttle point until after 90C, and if they hit over 100C, they'll automatically shut down to prevent damage. If you want to maintain lower temperatures to extend its longevity as much as possible, buy an aftermarket cooler that's more substantial than the crumpled-up soda can Intel calls a cooler.