People are being advised to take precautions against overheating and sunburn – even if the weather is cloudy.

Damien Adams, the County Council's Head of Emergency Management, has warned that high temperatures could be dangerous, especially for the elderly, the very young, and for people with chronic or long term medical conditions.

"I would advise everyone to ensure they have enough essential supplies at home, or at least to avoid going out during the middle of the day, when temperatures are at their hottest," he said.

Listen to Damien Adams talking to Chris Rider, West Sussex County Council broadcast media relations manager.

Damien also advised:

Keep plenty of water to hand, and take some with you whern you go out

Always use high factor sun protection and a hat

Stay in the shade wherever possible

Use the coolest room at home

Drivers travelling around the county should take regular breaks and ensure they have a supply of drinking water with them.

Planning your journey before you set off could mean you avoid having to sit in long, hot traffic jams.

Damien added: "Never leave a child or an animal in a parked car during such hot weather, even if the window is slightly open. The heat can very quickly be lethal."

Employers and schools are also being advised to relax dress codes and ensure staff and pupils are allowed to remain cool during the working day.

Peter Evans, County Council Cabinet Member for Public Protection, added: "As it is likely that there will more hot weather in the future, it really is vital that people follow this advice, to help them keep well and keep working."