Russian health officials are warning people in Moscow to stay inside and avoid physical exertion as smog from the worst wildfires in modern Russian history smothers the city. Haze and smoke are spreading through Moscow's streets, even seeping into the Metro network, and some people are wearing face masks indoors. Reports suggest the city's mortality rate rose by at least 30% in July. The national death toll attributed directly to wildfires is 52. Nearly 560 fires were still burning across central Russia as of yesterday. Of these, 39 were peat bog fires, 27 of them in the Moscow region alone, accounting for the acrid smoke choking the capital. Daytime temperatures in Moscow remain close to 40C with little sign of relenting in the next few days.