On August 6, Russian President Dmitry Medvedev visited a Moscow ambulance station, accompanied by top health officials. He was told that the number of emergency calls has increased by about 10 percent lately, related to the heat and smog.

The acrid smoke, from thousands of square miles of wildfires, drove carbon monoxide levels in Moscow five times higher than what is considered safe, the Russian Health Ministry said.

Residents were encouraged to stay indoors. Many who did not could be seen wearing masks as they walked outdoors.

The Russian Ministry for Health and Social Development reported on August 6 that 52 people have died as a result of the extensive fires in central Russia. Another 72 people needed treatment, 43 of whom remain hospitalized, it said.

Fires were still burning on August 6 in 22 of the country's 83 regions.

Tens of thousands of firefighters have been deployed to extinguish nearly 600 raging wildfires covering 500,000 acres, among the worst ever.

The record heat wave gripping the country showed no signs of abating on August 6.

Temperatures climbed to 37 degrees Celsius in Moscow and hit 41 degrees Celsius farther to the southeast in Tambov. By Sunday, Moscow could reach 40 degrees Celsius, a figure never before officially recorded in the city.