London, Aug 29 : A heated car seat may keep your bottom warm and toasty on a cold night, but the extra 'luxury' might be silently frying your chances of becoming a father, says a new study.
Scientists warn that the seats could damage sperm production by raising men's temperature to unhealthy levels.
An optimal temperature of between 35 and 36 degree Celsius is needed to produce healthy sperm. This is one reason why the testicles hang outside the main part of the body.
To test whether heated car seats might be raising scrotal temperatures above this threshold, Andreas Jung at the University of Giessen in Germany and his colleagues fitted temperature sensors to the scrotums of 30 healthy men, who then sat on a heated car seat for 90 minutes.
An hour in, and scrotal temperature had already risen to an average of 37.3 degree Celsius, with a maximum temperature in one man of 39.7 degree Celsius. Men who sat on unheated car seats reached an average scrotal temperature of just 36.7 degree Celsius, reports New Scientist.
Although that's only a slight increase due to the heated seats, Jung notes that it may nevertheless be enough to damage the sperm production process.
Sitting in a car for long periods of time, even without a heated seat, is already known to raise scrotal temperatures. And previous research suggests that couples take longer to conceive if the man drives for more than 3 hours a day.
The team did not test the effect of the heated seat on sperm quality or quantity.