['Male reproductive health has deteriorated in recent decades. It is proposed that increased testicular temperature in early childhood, due to the use of modern disposable plastic lined nappies (diapers), could be an important factor contributing to this decline.', 'Scrotal skin temperature was measured non-invasively in 48 healthy children aged 0-55 months (three age groups) for two 24 hour periods in randomised order (either cotton or disposable plastic lined nappies) using a portable, miniature recorder.', 'Mean 24 hour scrotal temperature (2880 measurements) was significantly higher in all age groups during the periods of plastic nappy use than with cotton nappies (p < 0.001). The rectoscrotal temperature difference was significantly higher with cotton than with plastic nappy use (p < 0.01).'] Is scrotal temperature increased in disposable plastic lined nappies?