I'd be worried at 45 degrees - that is warm for a pc. Until recently, I ran a small form factor pc with high performance components & it wasn't good at cooling - I did some readind on the subject and found that even samll measures such as clearing the dust from the fan blades periodically makes a difference to cooling efficiency.
You can go mad and install water cooling and all sorts of things, but a practical measure is to ensure that inside your case, all your leads are tidied away so that you ensure a reasonable airflow over the componentry.