Each facility shall provide heat for every bed room, bathroom and toilet compartment, and other habitable area, at a temperature of at least 68°F between 7:00 AM. and 11:00 P.M. and at least 64°F between 11:01 P.M. and 6:59 AM., every day other than during the period of June 15th through September 15th, in each year. The temperature shall at no time exceed 78 F during the heating season. For each degree less than -15°F that the temperature falls, the minimum temperature requirements may likewise be reduced by 1°F. The temperature shall be read at a height of three feet above floor level at any point in the room more than two feet from the inside of every exterior wall.
105 CMR, § 450.330