A fan is only any good in heat if your right next to it anyway unless its huge. Parties are THE hottest I have experienced especially one I attended in the basement of a glass warehouse a few years ago, I must of lost a stone.
Apart from punting in air-con premises which most WGs don't have in my experience its a case of grin and bearing it. Drinking plenty of water will keep you hydrated of course but you might need to piss a lot. I have air-con in my car so to and from a punt I am ok.
I can understand WGs and parlours not going to the expense of air-con (don't think I could cope with much driving today without it blasting in the car
) or having windows open to disturb the neighbours but dunno why they don't spend a little bit extra and invest in a cheap dehumidifier; as it's the stench of stale sweat plus other bodily fluids which makes rooms so darned unpleasant on days like this and all those fans do is swirl the same muggy air around and around