Final answer:
In hot weather, specimens should be shipped in a box with cold packs and a biohazard label to maintain a low temperature and ensure proper handling.
Step-by-step explanation:
According to standard precautions, the procedure for shipping specimens to a reference lab in hot weather is in a box with cold packs and a biohazard label. This is because cold packs help maintain a low temperature and prevent specimen degradation in hot weather. Additionally, the biohazard label ensures that the package is handled appropriately.