15 Miss. Code R. § 16-1-51.81.20
Suitable artificial heat shall be furnished to maintain 75 degrees F, inside temperature with 10 degrees F, outside temperature. Circulating hot water from a remote boiler or vapor-steam with circulating pumps and controls on emergency electrical service to provide heating in case of power failures are the preferred methods of heating. Electrical heating will be approved provided a standby electric generator is provided of capacity to furnish 80% of the maximum heating load in addition to other power and lighting loads that may be connected to it, or the facility is supplied by two electric service lines connected to separate transformers at the sub-station so arranged that electric services can be maintained in case of failure of one line or transformer. Direct fired units are forbidden except in areas such as laundries, storerooms, kitchens, and similar occupancies and then only if in ductwork or more than 8 feet above the floor. Open flame heaters are prohibited. Gas fired ranges and other appliances (except Bunsen burners) may be used where no hazard is created, but must be services with rigid pipe connections. Gas fired sterilizer, water heater, and other like appliances shall have provided adequate air intake for combustion and full venting for combustion products. No hall will be used as a plenum. Mechanical ventilation shall be installed in all toilets and janitors closets.
15 Miss. Code. R. § 16-1-51.81.20