If you wake up sweating profusely in bed, the first thing to look at is whether the heating is too hot in winter or the high temperatures in summer when the room is poorly ventilated. Secondly, consider the presence of sleep apnoea syndrome, usually seen in people with a chubby physique, where heavy sweating occurs due to breath-holding during sleep. In addition, tuberculosis and rickets can also be associated with night sweats and you may wake up to find your bedding and clothes damp and sweaty. This is a good time to go to hospital for an examination to clarify the cause.