Hydrocarbon fuel cell? 600 degrees Celsius. Large Hadron Collider? -271 degrees. Microwave drill? 2,000. Your run of the mill Core i7 MacBook Pro can't compete with these extreme temperatures, but that doesn't mean it can't get pretty darn warm under pressure. PC Authority recently put the latest edition of Apple's sleek silver classic through a series of torture tests, and found that running Cinebench could cause the CPU temperature to climb over 100 degrees Celsius. The metal shell proved ineffective at dissipating the heat as well as the similarly equipped Fujitsu Lifebook SH760, which finished the same test at 81 degrees, and actually required PC Authority to run the MacBook Pro on its side (see pic above) to complete certain tests. The site thinks that Apple's cooling solution may be inadequate for a Core i7, but these results could be a fluke -- in our experience with the machine, we actually noticed an improvement over the egg-cooking solutions of yesteryear.
Update: We'd like to point out that the temperatures described were related to the CPU internally, and not the actual case of the laptop.