A package of Class 7 (radioactive) material must be designed, constructed, and loaded so that--
(a) The heat generated within the package by the radioactive contents will not, during conditions normally incident to transport, affect the integrity of the package; and
(b) The temperature of the accessible external surfaces of the loaded package will not, assuming still air in the shade at an ambient temperature of 38 C (100 F), exceed either--
(1) 50 C (122 F) in other than an exclusive use shipment; or
(2) 85 C (185 F) in an exclusive use shipment.