Medical laboratories are located inside of most modern hospitals. These labs are used to identify biological pathogens from swabs, blood, and tissue samples. In the lab cultures are carefully created and allowed to mature requiring refrigeration.
Storage of untested and surplus specimens may also need to be refrigerated until they are needed. By refrigerating specimens just above freezing decomposition of the sample can be suspended. There are also many outside medical laboratories that do specialized testing for diagnosing and other medicinal studies. Incubation periods in temperature controlled units or rooms are necessary for testing to be done in a controlled setting. Large scale laboratories have specialized types of testing equipment that also require cooling to prevent overheating. Some of these are ultra/high-speed centrifuges, gas chromatographs, fume hoods, and autoclaves.