German research has found that heated car seats can lower a man’s sperm count.
The ideal temperature for sperm production is around 95F to 97F, just below the average core body temperature of 99F.
But when the German scientists tested 30 brave volunteers who sat on a heated car seat for just 90 minutes (the length of a football match) temperatures had risen to an average of 100F.
One over-heated individual recorded a temperature of 103.5F, New Scientist magazine reported.
Even those sitting on an unheated seat experienced slightly raised temperatures of around 98.1F – higher than the ideal sperm warmth.
Other research has found that men who sit in a car for more than three hours a day could be jeopardising their fertility.
Dutch research found that men who wore tight-fitting underpants for six months had significantly lower sperm counts than their loose boxer-wearing peers.
So long-distance distance lorry drivers with tight underpants and heated seats are probably not the ideal partner material for ladies keen to start a family.