Campsites have shower blocks. They house the lavatories, showers and wash basins for the campers. The facilites are, in general, free, but the showers have a pay-to-use mechanism, usually costing so much per minute. (The best way to ensure a hot shower is to go in immediately after someone has come out. That way, you don't have to waste your precious minutes waiting for the water to warm up.)
Showers in shower blocks have a 'turny-dial system' of temperature control. In accordance with all 'turny-dial systems' they have two settings: very cold and extremely hot. There is no in between.