Scientists looking into the claim that a person loses "most of their heat from their head" have found it to be nothing more than hot air.
Researchers, writing in the British Medical Journal (BMJ), also exploded the theories that sugar makes children hyperactive and eating close to bedtime is bad for the hips.
Experts from the Indiana University School of Medicine took six common myths and decided to examine the evidence to see if they were true.
They found no evidence that more heat escapes from the head than any other part of the body, and rather than children behaving in a different way after having consumed sugar, it was in fact parents' perceptions that change – seeing children as more unruly even if the sugar consumed was actually a placebo.
They also shot down alleged cures for hangovers and the myth that the Christmas plant, poinsettia, was toxic.
Meanwhile, evidence from Japan found that the suicide rate was lowest in the days before a holiday, and highest in the days afterwards, effectively debunking the myth that more suicides occur in winter.
In Finland, suicides peak in autumn and are lowest in the winter and, in Hungary, they are highest in the summer and the lowest in winter.