That's the Why

Why is there a myth that we we lose most of our body heat through our heads?

You have probably heard the assumed wisdom that you lose the bulk of your body heat through your uncovered head.

Well, all concerned, winter-hat-wielding mothers and grandmothers of the world take note: while hats do help stave off the effects of chilly elements, it seems we don’t pump out most of our warmth through our unshielded scalps.

Write-ups in the British Medical Journal (2008) and the New York Times (2006) suggest the idea arose from military experiments where hat-less subjects wore polar survival suits in cold conditions – but because most of the body was protected by the suit, the heat tended to exit through the exposed penthouse.

"Any uncovered part of the body loses heat and will reduce the core body temperature proportionally," write Rachel C Vreeman and Aaron E Carroll in the BMJpiece, which targets medical myths. "So, if it is cold outside, you should protect your body. But whether you want to keep your head covered or not is up to you."

Another seasonal myth in their sights is that poinsettias, which are often used as decorations around Christmas, are highly toxic. Not so, they argue, citing a 1996 article in the American Journal of Emergency Medicinewhich looked at 22,793 cases of reported poinsettia exposure.

“The majority of exposed patients [96.1 per cent] were not treated in a healthcare facility and 92.4 per cent did not develop any toxicity related to their exposure to the poinsettia,” it reports.

Still, it’s best to admire the plant rather than eat it. And to wear a hat if you feel like it.