As long as it has a decent heatsink. My bro once bought some P166 systems for the local library. These things were cheap, literally in every sense of the term. After 3-4 months both systems began crashing/locking up. After bringing them home and goofing around with them, he noticed that the fans were running very slow on one system and that the fan on the other needed a push to get going! Needless to say, he replaced the hs/fan with a better hs/fan and all problems were solved.
Anyway, almost any SS7 hs will be enough to keep a P133 cool, but the more standard Pentium hs will likely be insufficient.