Thermoregulation is not simply a matter of body surface area (BSA); it also has to do with vascularization of the area. For example, in the reverse case of hypothermia, where hyperthermia is the problem, it is not uncommon to place cold packs in the groin area and under the armpits and sometimes round the neck region. Why? Because these areas contain major blood vessels, yet represents probably less then 2% of BSA. Likewise, the head, while comprising approximately 9-10% of BSA does have an increase in vascularization over other parts of the body. In addition, as noted by others, insulation by body fat has an effect on heat loss/retention in any particular area of the body and the head has little body fat for insulation.

If I remember correctly, in the impromptu study, thermal sensors were placed on various parts of the body (and presumably in the rectum to monitor core temperature) then used to examine the surface skin temperature of various parts of the body/core. This was then used to “debunk” the myth to “wear a hat if your feet are cold” paradigm. What they should have used is a thermal imager looking at heat loss/retention of the whole body under various conditions.

One thing to keep in mind is it that infants and young children have a larger BSA of the head then teens and adults. Therefore, even under their theory (with which I do not agree) children would be at greater risk for heat loss through their heads.

Pete