What should divers use to prevent losing heat from their heads during a dive?

Using a hood is essential for divers to prevent heat loss from their heads during a dive. The human body loses a significant amount of heat through the head, and wearing a hood effectively insulates this area, helping to maintain body temperature in cold water environments. Hoods are typically made from neoprene, which is a material that offers thermal protection and helps to trap a layer of water against the skin, while also preventing cold water from flowing freely around the head.

In contrast, a face mask primarily serves to enhance visibility underwater and protect the eyes, but it does not provide the same level of thermal insulation as a hood. A scuba tank holds the compressed air needed for breathing during a dive, and while a diving suit provides thermal protection to the body, it may not cover the head effectively unless it is a full suit with an integrated hood. Thus, the most efficient way to insulate the head and prevent heat loss during diving is with a dedicated hood.