A heatwave has engulfed central parts of European Russia, and Siberia since June, destroying crops covering an area the size of Portugal. Green groups, including Greenpeace, say the temperatures are evidence of global warming.

"The all-time record has been broken, we have never recorded a day this hot before," said Gennady Yeliseyev, deputy head of Russia's state weather agency. The previous high of 36.8 degrees Celsius was recorded on August 7, 1920, he said.

"The new record could be broken by Wednesday," he said. Muscovites have struggled to deal with the heat, with most electronics retailers selling out of fans and air conditioners, and many cafes running out of ice and cold beer by early afternoon.

Women were using golf umbrellas to shield themselves from the sun on Red Square. Bloggers have begun to complain of men travelling with bare torsos on the metro.

"This summer is very hard, physically and emotionally," said accountant Marina Veselkova, trying to cool off by a fountain in front of Bolshoi Theatre after sending her children to relatives in the country.

"It's very bad," said Alexander, a courier. "I go to the beach at the weekends but it's difficult to swim because the water is so hot."

CROPS SUFFER

Russian grain prices shot up last week on advancing drought. The Agriculture Ministry said late on Friday that by July 22 drought had killed crops over 100,000 square kilometres (38,600 square miles), an area larger than Portugal.

Muscovites' discomfort was compounded on Monday by a blanket of smog, whose sharp, cinder-filled smell permeated the city and crept into offices, homes and restaurants via windows and doors.

The emergencies ministry said 34 peat fires and 26 forest fires were blazing on Monday in the area surrounding Moscow, covering 59 hectares (145 acres).

"Muscovites will have to inhale smoke for another two to two and a half months," said Alexei Yaroshenko, head of the forest programme at Greenpeace Russia. He said the smoke could eclipse the worst smog registered in Moscow, in 1872 and 1837.

Airports serving Moscow were unaffected by the smoke. "This is awful. It is going to damage people's health," said telephone engineer Davit Manukov, 25, standing by the Kremlin where black clouds of smoke enveloped its golden onion domes.

The Moscow government agency overseeing air pollution, Mosekomonitoring, told Reuters the amount of harmful impurities in Moscow's air exceeded the norm by 5-8 times.

The elderly and those suffering from heart disease should try and avoid contact with the smog, said its chief specialist Alexei Popikov, adding that the levels of carbon monoxide and nitrogen oxide were high.