I've had my MacBook for a week now and generally like it but, like many, have been concerned about the heat (yes, another MacBook heat thread ). The bottom-left of my MacBook gets pretty hot -- it won't burn skin (not yet!), but it is not something you want to touch for too long at all. "Hot" -- as opposed to "warm" -- would be the word for it. I installed CoreDuoTemp and have noted down some of the results. Please keep in mind that these aren't entirely thorough -- I've been a PC user for many years and just switched, so I currently don't have any software to really max out the MacBook. I just tried running a few pre-installed programs to see what would happen. By the way, the room I use it in is always between 67 and 74 degrees. Surfing the internet in Safari just after startup, CDT was in the high 30s (Celsius). Watching a video on YouTube a few minutes later -- temp went from 48, to 54, then to 58 C. When the video ended, it went back down to 50. I then ran a Quicktime HD trailer at 720p. The temp rose to 63. A few minutes after the video, it dropped to 48. When I started writing email, the temp rose to 56 C. By the way, during this time the CPU didn't exceed 30%. Interestingly enough, I got the highest temp readings when running on battery power, with the battery setting at "Normal." Running Firefox with two tabs open, my MB was at 67 C. Then, running the pre-installed chess program, which brought the CPU to about 50%, the temp got to 72 C. So, here are my questions: 1) From what I've read on these forums, it seems that my MB is running a bit cooler than others. Is that the right way to read these results? Do these results seem "within spec" for the particular tasks I'm doing? If this is the case, I'd be curious to know why the bottom gets so hot. 2) Anything else I might run to test the temperature? 2) If my MB gets to 72 C on battery when running chess, do you think it'll get dangerously hot if I'm multitasking in Photoshop, Dreamweaver, and other programs while I'm on full electrical power? I don't have these programs for Mac yet, but if I keep using the MB I probably will. Any thoughts would be appreciated. By the way, I do get the "mooing", but for me it's not a big deal provided the MB is supposed to do that.