We were gigging at a block party in Queens NY many years ago (late 70's). We had played the second set for about an hour and needed a rest. The drummer, however, was full of energy and embarked on a looooong solo while the rest of the band took a bathroom/beer/joint break. The drummer finished up his solo after about 20 minutes, and said he would be ready for the 3rd set in five minutes. He sat back down at his kit, and about 20 seconds into the 1st song, he got a severe cramp in both legs, stopped playing, jumped up and tried to walk the cramps off. We never let him play a drum solo again !