D.C. Mun. Regs. tit. 25, r. 25-F603
All restrooms, locker rooms, and toilet rooms shall be adequately ventilated so that excessive moisture is removed from the room. Acceptable ventilation includes mechanical exhaust ventilation, a recirculating vent, or screened windows.
Each system for heating, cooling, or ventilation shall be properly maintained and operational at all times when the rooms are occupied.
Every tanning room within the facility shall have a thermometer mounted at five feet (5 ft.) above the floor. Adjacent to the thermometer shall be a sign that states: Patrons shall not tan if room temperature is at one hundred degrees Fahrenheit (100 °F) or (thirty-eight degrees Celsius (38 °C)) or higher. Please report excessive heat to the operator immediately.
All restrooms, locker rooms, and toilet rooms shall be capable of being maintained at a temperature between sixty-eight degrees Fahrenheit (68 °F) (twenty degrees Celsius (20 °C)) and eighty degrees Fahrenheit (80 °F) (twenty-seven degrees Celsius (27 °C)) while being used by customers.
The use of portable space heaters is prohibited.
D.C. Mun. Regs. tit. 25, r. 25-F603