The study found that the majority of men who were exposed to high temperatures at their workplace—welders, dyers, blast furnace workers, and those employed in cement and steel factories—were more prone to infertility. This is because the additional environmental heat increases the temperature of the scrotum, causing a negative effect on sperm production. Over 12-18 million couples in India are diagnosed with infertility every year. AIIMS doctors say a one-degree elevation in testicular temperature leads to a 14% depression of spermatogenesis. Infertility on the rise among Indian men - The Times of India