Here is more info on Wincooler: WinCooler is a low power idle process for Win95/98 that cools your CPU by halting it when it is idle. This extends the operating life time of your CPU, and reduces power use and heat.
WinCooler detects when the operating system is idle, and calls the CPUs HLT command, which puts the CPU into low power mode. This method of cooling has been built into x86 microprocessors since the 486, and was designed by microprocessor engineers. Linux, Windows NT, and OS/2 have a built in low power idle process which does the same thing, allowing them to run cooler and use less power. WinCooler makes this technology available to Win95/98 users.