ghnader hsmithot :
It would start a fire.
I myself had seen 2000 fires started from bad applications of heatsinks and seen over 1400 burned because of them.The rest of the mates that i had seen also had there faces hideously burned and disfigured due to the fact that the cpu was soo hot that it shot itself like a bullet right off the motherboard and went through their cheeks, jaws etc.
And i almost started believing you, good joke, overclocked cpu without heatsink can actually explode.
Thank you all for your answers. This K6-2 is for a small ftp server, it does not have an overheating protection and it does not have heat sensor, i can't see temperature but heatsink is placed properly with good thermal paste, so i don't know if it's a good idea to use it, but i get a good feeling when making use of such old school components, maybe i should get a gsm fire (smoke) alarm..