The Health Ministry has issued instructions to hospitals and old age homes about keeping patients safe and comfortable during the upcoming severe heat wave due during the next few days. The elderly and the chronically ill, as well as babies and young children, should not be exposed unnecessarily to heat or sun, and their physical exertion should be reduced to a minimum. They should drink plenty of water and stay, preferably, in cooled rooms. More information can be found (in Hebrew) on the ministry's Web site at www.health.gov.il. Magen David Adom issued its own advisory on Thursday. To prevent dehydration, people should drink more than they need to quench their thirst, and to rest in a cool, shady place. Cold drinks are better than hot ones. If a person shows signs of dehydration, such as confusion or headaches, stop physical activity and drink cold water. If it is serious, call MDA at 101 and cool the victim off by removing some of his clothing, fanning him and sprinkling water on him.