There is a product on the local market in New Zealand called "Showerdome" that is a clear plastic dome that can be attached over the top of most open top showers.
Covering the top of a shower reduces the convection air flow that naturally occurs when showering, as well as increasing the humidity while showering, which has the effect that one feels warmer and can turn the temperature down and reduce hot water use. It also heavily reduces the steam escaping the shower, so also heavily reduces condensation and associated mould problems in the bathroom.
However, "Showerdomes" are quite expensive. Are there other designs or products available for achieving the same result?