It really depends on the operating conditions versus the ambient conditions. If you are running hot and have a well cooled environment, this can cuase some damage. The types of questions you need to ask yourself are things like, how long do intend to keep this equipment. If only two years or so, it's not likely that these stresses will build up enough to break components in that time period. So, maybe you'll save on electricity bills than replacing components. The equation changes over time, of course. Speaking from personal experience, I've never had hardware failure occur while running, only during boot up. So, there's some anecdotal evidence about the issue.