The forest fires have left Moscow looking like a city under siege. Thick brown smoke covers the capital, giving it an eerie feel, and bringing with it an obvious health risk. Residents are being asked to remain indoors; many who venture outside wear special breathing masks, and many more are suffering from breathing disorders. The situation is so bad that smoke has even made it's way underground - into the city's famous metro rail system. But perhaps the most vulnerable to the smoke, are the children.