HOT weather can do serious harm to your health, NHS chiefs in Cambridgeshire warned this week. Although many people enjoy the strong sunshine, vulnerable groups, such as elderly people and young children, needs to take care to protect themselves from the harmful effects of the sun and heat. The advice from NHS Cambridgeshire is to keep out of the heat as far as possible, try to stay cool, drink water or fruit juice regularly, and seek advice from a doctor, pharmacist or NHS Direct if you feel unwell or develop unusual symptoms. Health chiefs advise planning your day to avoid being outside during the hottest hours - 11am until 3pm - confining strenuous activity to the early morning and evening, stay in the shade, and wear a hat and loose-fitting clothes. Shutting up your home by day and ventilating it by night - second nature to people who live in Mediterranean countries - will help to reduce the discomfort of a heatwave, and cold water or a damp cloth on the face and back of the neck will make you feel more comfortable. NHS Cambridgeshire advises drinking regularly, even if you do not feel thirsty, and avoiding alcohol, tea and coffee. You should eat normally and favour cold foods, such as salads and fresh fruit.