The thick smoke that's suffocating Moscow has even got into the capital's metro.
The air in Moscow is thick with smoke as fires approach the capital from the south.
Air contamination is now seven times normal levels, making it dangerous even for healthy people, say doctors, who advise everyone to stay indoors.
Visibility on roads has dropped at times to as low as 20 meters, and the smog has descended into the metro, too.
Millions of passengers who use Moscow metro every day are being affected.
Temperatures down there hit a record high on Wednesday: 34 degrees Celsius.
Now Muscovites can't even hide from the heat wave underground.