Call to avoid rush hour in heatwave
Employers should allow staff to travel outside rush hour to avoid overcrowded public transport, health chiefs have said, as Britain sweats on the hottest day of the year so far.
Drivers on one of Britain's busiest motorways faced delays of more than an hour this evening in sweltering heat after a serious accident left one carriageway closed.
The heatwave could trigger a national alert and Public Health England (PHE) has urged people to look out for those who may feel unwell in the hot weather after temperatures of 29.1C (84F) were recorded at Heathrow Airport this afternoon.
Dr Angie Bone, head of extreme events at PHE, said the heat could be dangerous for older people, young children and those with serious illnesses, and urged employers to be flexible.
She said: "During very hot weather, pregnant women and people who have chronic illnesses, including cardiovascular, respiratory, renal conditions, diabetes or Parkinson's disease, may experience discomfort if indoor temperatures are particularly hot and in using public transport.
"Employers should ensure indoor areas are kept cool and consider allowing these individuals to travel to or from their place of work during cooler, or less busy times of the day. For those working or exercising outdoors, strenuous physical exertion during the hottest part of the day should be kept to a minimum."
Her comments were supported by TUC general secretary Frances O'Grady, who said: "Many people travel to work on overcrowded trains or buses, and doing that during the heatwave will be particularly unpleasant.
"Sensible bosses will allow their staff to work flexibly so that they have the option of varying when they arrive and leave to avoid the sweltering conditions of the rush hour commute."
A car and a van were involved in an accident on the M25 between junction 9 at Leatherhead and junction 8 at Reigate in Surrey, Highways England said.
All lanes on the eastbound anti-clockwise carriageway were closed, the agency said, with delays of around 60 minutes and queues back to at least junction 10 at Cobham.
Police and officers from Highways England were at the scene and motorists left their cars to seek shade on the hard shoulder.
Hot conditions at Wimbledon forced officials to reduce capacity to allow fans to cope.
Forecasters said the mercury hit 29.3C (84.7F) in SW19, with a chance that by the end of the day it could reach 30C (86F).
A Wimbledon spokesman said: "We have reduced today's initial capacity slightly to 38,000 to allow people more room in the grounds and therefore more space in the shade and easier access to the free water points.
"Assuming all is going well we'll be letting more people in as the day progresses.
"The daily capacity is dependant on the number of courts in operation and the prevailing weather conditions so it would not be the first time we have regularly adjusted the daily capacity."
Tomorrow is expected to be even hotter, with temperatures predicted to hit 35C (95F), making a level 3 heatwave alert likely.
The highest recorded July temperature was at Wisley, Surrey, in 2006, where the mercury peaked at 36.5C (98F).
The level 3 alert - one below a national emergency - is triggered when the Met Office confirms a 90% chance of heatwave conditions. When the alert is issued, social and healthcare services must mobilise community and voluntary support for high-risk groups and media alerts about keeping cool are issued.
Professor Paul Cosford, director for health protection and medical director at PHE, said: "Local authorities and the NHS should now be familiar with PHE's Heatwave Plan, which aims to reduce health risks related to heat. Those looking after schoolchildren or pre-schoolers during the hot spell should ensure they've read the guidance in the plan, which includes specific advice on how to keep children safe on very hot days.
"While hot weather is enjoyable for most people and uncomfortable for some, sadly experience tells us that exposure to excessive heat can kill, with most cases of illness and death caused by heart and lung disease. Because we are not used to these very hot temperatures in England, it's important that local plans are in place to reduce the impact of harm from very hot weather."
The heat has also caused problems for rail services, with t rain companies having to cancel journeys or slow them down after Network Rail warned tracks could buckle in the heat.
Several fast trains from London Paddington were cancelled after Network Rail imposed speed restrictions to protect track points.
Some passengers will have to take slower services to Henley-on-Thames and Bourne End, changing at Twyford or Maidenhead.
A spokesman for the company said: "First Great Western is advising passengers that due to the anticipated hot weather Network Rail is to impose a speed restriction in the London Thames Valley area to protect track points on Tuesday June 30.
"As a result there will be no fast trains between London Paddington and Bourne End or Henley-on-Thames from 1200 until 2000."
Health warnings were issued for people suffering from lung conditions.
Vicky Barber from the British Lung Foundation Helpline said: "During hot weather, the air we breathe has lower moisture levels than usual, which can have a drying effect on our airways. As a result, people with respiratory conditions such as COPD (chronic obstructive pulmonary disease) or severe asthma may find it harder to breathe, feel more tired, or find their lungs feeling heavy or tight."
She recommended that people with lung conditions avoid going outside at midday, wear loose clothing and drink plenty of water.
The heatwave is being caused by a warm front and tropical continental air mass from Europe pushing across the country, bringing high temperatures, humidity and possibly Saharan sand.
Paul Knightley, forecast manager at MeteoGroup, warned that dust whipped up from the Sahara is being carried by the wind towards Britain where it could coat cars.
Mick Cash, general secretary of the Rail, Maritime and Transport union, said: "It's bad enough travelling on Britain's rammed-out, overcrowded trains at the best of times, let alone when temperatures are heading to boiling point and our members are on full alert to assist passengers who are in distress.
"It is only right that some serious leeway is given to workers in the expected heatwave conditions and once again this situation reinforces the importance of having train and platform staff on hand and trained to deal with any eventuality."
Thameslink passengers were also affected by rail restrictions.
The company tweeted: " Due to the high temperatures, there are several speed restrictions in place across the network which may delay your train at short notice."
Northern Rail said speed restrictions were imposed between Kearsley and Moses Gate, causing delays of up to half an hour between Salford Crescent and Bolton.
A Network Rail spokeswoman warned all train passengers to expect delays during rush hour, and again tomorrow as the mercury is set to rise.
"There are speed restrictions all over the country due to the hot weather so there will be some delays and some disruption.
"We apologise to passengers for delays but obviously the restrictions are in place to minimise disruption on the network."
Rail company Southeastern said Network Rail had advised it that it would be imposing speed restrictions across many parts of its network during tomorrow afternoon and evening.
It said in a statement: "This is likely to cause disruption to trains although we will be aiming to run all services."
People might wish to avoid travelling between 1pm and 7pm, it added.
A number of coastguard rescue teams helped police who have been implementing Operation Stack on the M20.
Teams from Bexhill, Dungeness, Margate, Sheppey and elsewhere assisted with the distribution of food and water to lorry drivers queuing on the motorway in Kent because of delays caused by industrial action in Calais.
Tracy Hawke-Treneer, Dover Coastguard's watch officer, said: "As an emergency service we have the capability to respond to major incidents when needed, however this does not impact on our maritime search and rescue response capabilities.
"The teams will be working into the night to make sure that people are receiving food and drinks.
"Work will resume in the early hours of the morning to continue to distribute sustenance as it arrives."