What percentage of heat can divers lose through their heads?

Divers can lose up to 75% of body heat through their heads due to several physiological factors. The head is a highly vascularized area, meaning it has a dense network of blood vessels that can lead to significant heat loss. When a diver is in water, especially cold water, the head may not be insulated as effectively as other parts of the body, such as the torso, which is typically better protected with thicker layers of wetsuit or drysuit material.

Moreover, since the head represents a relatively small surface area compared to the rest of the body but contains a large amount of blood flow, any heat loss from this area can disproportionately impact overall body temperature. This is particularly important in diving, as maintaining core temperature is crucial for performance, safety, and comfort while submerged.

The significance of head heat loss highlights the importance of wearing appropriate headgear, such as hoods, to help reduce this heat loss during dives, especially in colder conditions. This awareness aids divers in making informed decisions about their gear and preparation for dives.