Geek.com Geek News - Intel's 486 CPU turns 15: "It is not 'hearsay', it is fact. P4s run hot. I have a P4-M in my laptop here, which I don't dare put on my lap for more than a couple minutes. Even on low power settings it dissipates so much heat that I have actually burned myself (we're not talking a serious burn, here, it just hurt and was red for a few days) by touching it.

Now I'm not saying that Athlons always run cooler, although in my experience that has been the case (except for old Athlons, they were pretty bad about heat dissipation). P4s do run very hot, I have empirical and experiential evidence to support such a claim, and there is no way you can convince otherwise."