The authorities in Italy have declared a red code for particularly dangerous heat in 15 cities, ANSA and France Presse report, quoted by BTA.
Among these cities today are Milan, Florence and Rome. A code will be issued for 16 cities tomorrow.
The Italian Ministry of Health recommends that Italians in the heat not consume heavy foods, stay home during the hottest hours and pour cool water over themselves.
Today, temperatures of up to 38 degrees Celsius are expected in places in Italy.
This morning at around 10.45 am, temperatures in places in Florence were already 35.1 degrees Celsius.
A red code has also been issued for 54 departments in France. Meteorologists predict that temperatures in places will reach over 40 degrees Celsius. A red code for heat has been issued for 35 departments. These departments are home to a total of 90 percent of the country's population.
The heat wave is expected to last until the end of the weekend.
The authorities have banned the consumption of alcohol in departments where there is a red heat code. The management of the state railway company also recommends that passengers from the most vulnerable categories not travel by train in the heat.
Yesterday, absolute temperature records were set in a number of cities in the country. In Angers, thermometers recorded 40.9 degrees Celsius, in Saintes - 42 degrees Celsius, and in Bordeaux - 41.9 degrees Celsius. In Châteaumeyen, the highest temperature of the day was recorded - 43.3 degrees Celsius.
Over the weekend alone, 20 people drowned in the country while swimming in various bodies of water.
A red code for dangerous heat has also been issued for parts of southern Britain for tomorrow and Thursday - which is rare for the country.
In the UK, the historical temperature record for June is 35.6 degrees Celsius in Southampton in 1976 and in Camden Square in London in 1957.