Hot weather smog alert

Holiday makers on the road will only add to the smog

Millions of Britons have been suffering in the sun as the hottest weekend of the year caused widespread air pollution and some major traffic jams.

Weathermen said blistering conditions across the country had produced the highest temperatures of the summer so far, with thermometers at Heathrow Airport reaching 31C (88F).

But the heat sparked high ozone readings from London to Cardiff.

Doctors warned asthma sufferers to stay indoors and seek medical help if they suffered extreme symptoms.

Doctors have warned about the strength of the sun's rays

A spokeswoman for the National Asthma Campaign said: "Hot weather can be a particularly difficult time for asthma sufferers and others because of the accompanying air pollution and high ozone readings.

"Ozone is particularly dangerous because it can trigger asthma attacks. We are advising sufferers to check their equipment, stay inside, seek advice from their GPs and seek medical help if they experience an extreme attack."

Doctors also warned sunbathers to limit their exposure to the sun's rays and to drink plenty of fluids to avoid dehydration.

The Health and Safety Executive also called on employers to bring in air conditioning for those who have to work over the weekend to help them cope with the heat.

Traffic gridlock

But the lure of the sun was already proving too much for many drivers who headed straight to the beach determined to make the most of the weather.

Roads out of the major conurbations and towards the coast were generally busy with severe problems in the south west.

Thousands of sunseekers were trapped on packed roads as the exodus to Somerset, Devon and Cornwall caused queues of up to 15 miles on the M5 near Bristol.

However the humid weather ushered in isolated thunderstorms in some areas, and brought downpours to central London, East Anglia and the East Midlands.

Monitoring centres run by the Department of the Environment recorded the highest levels of ozone in Cardiff, south Somerset, Wicken Fen in Cambridgeshire, Thurrock in Essex and areas of west London.