microprocessor overheating

Can anyone tell me what is a possible relationship between processor speed and heat generation?

As ChipDeath pointed out, heat output and processing power are closely related but the ratio linking the two does vary between each stepping (generation) and architecture (manufacturer design) and even between individual CPUs sharing the same specifications.

Within the same stepping of a particular architecture, the heat output will scale almost linearly as the operating frequency increase. Note that manufacturers will sometime chose to increase the default voltage along with the operating frequency, which will contribute to a greater increase in heat output.

You also need to understand that manufacturers have different methodologies when it comes to disclosing the thermal and electrical specifications of their CPUs and that temperature readings can vary a lot, even between seemingly identical computers (same model of motherboard, CPU and cooling system).

So in short, yes, there is a relation between CPU speed and heat output but so many factors play a role that it is not possible to directly link the two.