'Heat Dome' continues to drive mercury to record highs across Europe

Much of western Europe is baking under a "heat dome" as temperatures soar toward 40 degrees Celsius in a number of cities.

France, Italy, Spain and the UK are issuing warnings about the risk of extreme heat affecting tens of millions of people.

The UK recorded its hottest June day, with 35.8 degrees reported in Surrey, southern England.

UK's Met Office issues the red warning, which it says are "reserved for the most severe events."

The agency is expecting significant health impact from this heat wave.

Meanwhile, Londoners are taking plunges to cool down, with many spotted swimming and kayaking in parts of the River Thames, seeking reprieve from the blazing temperatures.