Start with the manual
Before considering a heater for a bathroom, find explicit manufacturer instructions for that location. If the documentation does not address the intended use, ask the manufacturer before proceeding. Source: editorial
Keep electricity away from water
Keep portable electric heaters away from water. Never touch an electric heater while wet. Source: cpsc
Make installation a separate decision
For a fixed installation, bring the room layout and proposed model to a qualified installer. This guide does not determine electrical zones or certify a product for wet locations. Source: editorial