A ventilation opening into the sauna room shall be provided. The opening shall be not less than 4 inches by 8 inches (102 mm by 203 mm) located near the top of the door into the sauna room.
The following permanent notice, constructed of approved material, shall be mechanically attached to the sauna room on the outside:
WARNING: DO NOT EXCEED 30 MINUTES IN SAUNA. EXCESSIVE EXPOSURE CAN BE HARMFUL TO HEALTH. ANY PERSON WITH POOR HEALTH SHOULD CONSULT A PHYSICIAN BEFORE USING SAUNA.
The words shall contrast with the background and the wording shall be in letters not less than 1/4 inch (6.4 mm) high.
Exception: This section shall not apply to one- and two-family dwellings.