The southern half of the country’s weather map is today covered in red.

The Met Office has placed regions such as the Algarve, Alentejo and Lisbon on a very high risk of exposure to the harmful rays of the sun, and the risk level is 9 out of possible maximum of 11.

People are asked to avoid spending excessive periods in the open, while the Met Office says children should remain indoors between 12pm and 4pm.