The Met Office has upgraded its heat watch warning to level three as temperatures continue to soar across the country.

Yesterday, tourists flocked to Bournemouth's beaches on Tuesday as temperatures hit highs of 27.9 degrees Celsius.

As the Met Office issued a level two heat warning for many parts of the country, sun seekers enjoyed the hottest day of the year so far by cooling off in Poole Bay and the new Pier Approach fountains.

Today, London and the south east are expected to see temperatures rise to 35 degrees, sparking a host of health warnings.

The Met Office upgraded its heat warning around 9.45am on Wednesday morning to an amber level three "heatwatch action" alert with a 90% chance of heatwave conditions for some last until 9am on Thursday.

Bournemouth Echo:

The Met Office warnings says: "The current hot spell will peak through the next 24 hours. Afternoon temperatures in the London area will reach the mid 30's Celsius. Slightly cooler in the far west, these conditions edging slowly eastwards accompanied by some thunderstorms."

The warning is triggered when the Met Office confirms threshold temperatures for one of more regions have been reached for one day and the following night, and the forecast for the next day has a greater than 90% chance the threshold temperature will be met. This stage requires social and healthcare services to target specific actions at high-risk groups.

Bournemouth is predicted to see highs of 24C today, while Blandford, Wareham and Verwood should all see 26C. 

Light rain and cloudy conditions have been predicted for Thursday with sunny intervals on Friday before rain moves in at night. 

Public Health England has warned beach-goers to ensure they are well protected from high UV levels with sunscreen of at least SPF15, loose fitting clothes, UV sunglasses and a hat.

The agency has also urged the public to keep out of the sun between 11am and 3pm, to drink plenty of cool liquid through the day and never leave children or animal in a closed, parked vehicle.

The technical definition of a heatwave is when the daily temperature exceeds the average by five degrees for five days or more.

10 facts about hot weather

1. “As cool as a cucumber” is true. The inside of a cucumber can be as much as 11C cooler than the outside temperature.

2. The balls at Wimbledon are stored in refrigerated containers at 20C until they are needed.

3. According to Nasa, when the temperature reaches 35C our work output drops by 45 percent.

4. The hottest day ever recorded in Britain was August 10 2003, where it reached 38.5C in Kent.

5. You’ll lose weight in the heat but you’ll gain it back when you eat and drink!

6. The heat stored by roofs, pavements and concrete structures can raise the night temperature in cities by as much as 22C.

7. Heat degrades your mobile phone battery, so keep it cool and out of the sun.

8. Hot water can freeze faster than cold water, although there is no definite theory on why this happens.

9. Bill Nye found that the minimum temperature to cook an egg outside was 55C, which took 20 minutes.

10. The hottest man-made temperature ever recorded is about 4 billion degrees Celsius!