Heat and humidity is a deadly combination and the fluid loss and inability to sweat will make body\'s internal temperature regulation go haywire, doctors said. The daytime temperature has been rising to the high 40s and in some areas as the humidity has shot up to more than 90 per cent making it very uncomfortable outdoors, even at night, according to the Met Office. \"Those who are not accustomed to the outdoors in the summer should take care and replenish the fluids lost. Sometimes, the dehydration can raise your temperature very fast,\" warned Dr Babu Shersad, specialist, internal medicine and nephrologist. He said dehydration then has a domino effect and can lead to muscle breakdown and in severe cases, kidney failure.\"When the sweat does not dry and fails to create the cooling effect on the body, then it can get very uncomfortable,\" said Dr Lalit Uchil, specialist family physician. He advised those who wish to exercise outdoors not to do so between 11am and 5 pm. \"Either very early morning or late evening, or find a cool gym,\" he said. When jogging outdoors it\'s best not to wear close-knit synthetic clothes as they are inefficient in absorbing moisture. The doctor recommends cotton clothes. He said dehydration leads to muscle cramps. \"The best way to get rid of the cramps [the muscle spasms] in your toes is to rehydrate quickly,\" said the specialist. The doctor said those who work outdoors do not have much choice except to get out of the direct sunlight. \"It is the reason that the UAE government has asked to give workers a break during the worst period of the day. But they need to be moved to a cool place with access to a fan or an air-conditioner.\"Dr Shersad said one can exercise and swim after Iftar when the body has been rested and the water replenished. From / Gulf News