Carriers and intermediate handlers must not commingle marine mammal shipments with inanimate cargo. All animal holding areas of a terminal facility of any carrier or intermediate handler where marine mammal shipments are maintained must be cleaned and sanitized in a manner prescribed in § 3.107 of this subpart to minimize health and disease hazards. An effective program for the control of insects, ectoparasites, and avian and mammalian pests must be established and maintained for all animal holding areas. Any animal holding area containing marine mammals must be ventilated with fresh air or air circulated by means of fans, blowers, or an air conditioning system so as to minimize drafts, odors, and moisture condensation. Auxiliary ventilation, such as exhaust fans and vents or fans or blowers or air conditioning must be used for any animal holding area containing marine mammals when the air temperature within such animal holding area is 23.9 °C (75 °F) or higher. The air temperature around any marine mammal in any animal holding area must not be allowed to fall below 7.2 °C (45 °F). The air temperature around any polar bear must not be allowed to exceed 29.5 °C (85 °F) at any time and no polar bear may be subjected to surrounding air temperatures that exceed 23.9 °C (75 °F) for more than 4 hours at any time. The ambient temperature must be measured in the animal holding area upon arrival of the shipment by the attendant, carrier, or intermediate handler. The ambient temperature must be measured halfway up the outside of the primary transport enclosure at a distance from the external wall of the primary transport enclosure not to exceed 0.91 meters (3 feet).