Wigs off in London heat

Yesterday the Met Office raised its heatwave alert from level two to three - one stop short of the maximum - as temperatures in London peaked at 30C for the second day in a row.

In an unusual step at the Royal Courts of Justice, barristers were allowed to take their wigs off in court three.

At the Wimbledon tennis championships, where rain rather than heat normally halts play, officials prepared to give women players an extra 10 minutes to rest between sets.

But there were no "extreme weather" breaks for British star Andy Murray during his fourth-round match against the Marcos Baghdatis on Monday afternoon. The 19-year-old Scot failed to find his rhythm and lost in straight sets to the Cypriot, who barely broke a sweat in the Meditteranean-style heat.

Animals at Chessington Zoo in Surrey, however, did get special treatment. The gorillas received their fruit and nuts frozen in ice blocks, while the tigers played with a block of ice filled with blood and hung from a rope.

On the Tube, fears that tracks may buckle in the heat prompted managers to order eight speed limits of 20mph on the District and Metropolitan lines.

London mayor Ken Livingstone warned that global warming could cause "loss of life" if a train broke down underground in a few years' time. "We might face ... having to shut some Tube lines on particularly hot days just because it won't be safe," he said.

"You reach a point where the underground will become literally intolerable and you could face the prospect of loss of life."

A groundwater cooling system is currently being installed for trial at Victoria station. Cold water already pumped out of the station will be used to cool hot air on the concourse and platforms.

New trains for the sub-surface Circle, District, Hammersmith & City and Metropolitan line, due to arrive in 2009, will also come with air-cooling.

The Met Office yesterday issued its new heat alert after confirmation "that a major heatwave will occur", a spokesman said. It is the first level three warning since the introduction of the Heat-Health alert system in 2004.

Over the next few days London has a 90% chance of experiencing temperatures of up to 32C, with lows of close to 20C, the spokesman added. "Very warm, humid air will persist across the southern half of the United Kingdom."

Today temperatures are due to rise to 30C in central London and 32C at Heathrow airport.

Hot air moving in from Europe is expected to cause heavy thunderstorms later this week. London is forecasted to be hit by downpours and potential flash floods on Wednesday and Thursday.

During the hot spell the elderly, children under four and the chronically ill are at risk of heat exhaustion and potentially fatal heatstroke, the health department warned.

In 2003, a heat-wave across Europe claimed 27,000 lives. Deaths of over-75s in London increased by more than 60% that summer.

"It's a fact that as people get older, their bodies cope less well with hot weather," said Gordon Lishman, head of Age Concern England.

"Basic precautions such as staying indoors or in the shade, drinking more, taking cool baths or showers, and keeping the home well ventilated sound obvious but will really help."

Symptoms of heat exhaustion include headaches, dizziness, muscle cramps, nausea and vomiting.

Heatstroke can develop if these symptoms are untreated, but can also occur without warning. It can spark intense thirst, confusion, convulsions and loss of consciousness, and ultimately brain damage or death.

In a public awareness leaflet, the health department advised people to drink more water or fruit juice but to avoid alcohol, tea and coffee, which make dehydration worse.

British Waterways (BW) also warned people not to swim in canals, rivers, docks and reservoirs around London.

Stagnant water can be home to stomach bugs and the potentially fatal Weil's Disease, which is caused by rats' urine entering the body through cuts and grazes. Hidden objects, slippery edges, passing boats and shock from icy water add to the danger, a BW spokesman said.