Some outdoor heaters can be used on a covered patio, but it’s essential to choose the right type, and to install it correctly, to avoid fire hazards or damage from heat. Electric heaters are typically safest for covered areas as they don’t emit harmful gases and can be installed with clearances that prevent overheating materials above them. For gas heaters, especially those using propane or natural gas, you must ensure adequate clearance above the unit and proper ventilation to avoid buildup of hazardous fumes.