Precautions advised as temperature forecast to reach 41C

The ministry stresses that heat stroke can be serious. The most vulnerable are the over-65s (especially if they live alone); babies and young children; people with chronic diseases and who take medications such as antidepressants, diuretics and antihypertensives; and people who work outdoors. Last summer, there was a death which was linked to exposure to heat when working.

Heat stroke occurs when the body temperature reaches 40C and the body cannot reduce it effectively. It is usually the result of prolonged stay in very hot environments or of intense physical activity when it is very hot. Very high body temperature can lead to a fast pulse, rapid breathing, cramps, headache, nausea, drowsiness and intense thirst. There may also be confusion, seizures and loss of consciousness.

At home, the advice is to ventilate rooms during the early and late hours of the day but otherwise close windows and draw curtains when the sun shines directly. Taking a shower at least twice a day is recommended, as is moistening the skin with wet towels. People are advised to go shopping or to undertake other business early or late in the day.

Other commonsense advice includes - never leave anyone (or an animal) inside a parked vehicle even with the windows down; avoid alcohol, as it dehydrates; don't overdo coffee, tea and sugary drinks; avoid hot and large meals; eat more fruit and veg and have meals with moderate quantities; drink plenty of fluids, even if you are not thirsty - water at room temperature and not too cold, fruit juices, gazpachos.