Smog covered Moscow on Wednesday as forest fires continue to burn.
The Russian capital has been wrapped in a grey haze for three days running as temperatures hit close to 40 degrees.
Officials said air pollution levels are eight times higher than normal.
Dozens of peat bogs are ablaze in the forests that surround Moscow.
Drought conditions have left the countryside parched and have destroyed crops covering an area the size of Portugal.
Firefighters have so far struggled to get the flames under control because of the sweltering heat.
Prime Minister Vladmir Putin has set aside 635 million euros to deal with the emergency.
European Russia and Siberia has been gripped by a heatwave since June in one of the country’s hottest summers since records began.