i ran an 030 50 for a long time with no heatsink or anything and never had a problem. cpus back then were designed to run without anything. a cpu that needed a heatsink or fan was considered "ineffecient"
an overclocked cpu or a early revision is a different story though. with a normal 030 50 you shouldnt be able to put your finger on the cpu it will get hot. if there are no system stability problems i would say just leave it or get a stickon heatsink.
