Upgrading a laptop hard drive

I recently bought my GF a laptop for her birthday and it's the first laptop I've owned. I was considering replacing the hard drive with a 7200RPM model and was wondering if I should be concerned about heat. The unit I bought seems to have good cooling ( there's a lot of heat coming out of the side vent) but I didn't want to replace it and end up overheating the CPU or something becuse it wasn't designed to dissipate that much heat. This is the laptop I bought, I got it last week for $649.00
http://www.tigerdirect.com/applica [...] CatId=1891

I looked at Toshiba's site to configure a L355 and the fastest option they give for a hard drive is 5400RPM which leads me to believe that it's not designed to handle the heat from a 7200RPM drive.

Also on a side note I noticed that the maximum memory it can handle is 2gb. That kind of annoys me because I was planning on installing 4gb, oh well.