Rome and Milan have ordered no-car days next week to combat pollution, which has hit unhealthy levels for weeks mainly because no rain has fallen to wash away the smog.

A six-hour ban on cars this coming Monday and Tuesday was announced by Rome Thursday, while Milan’s anti-pollution measure sees six-hour bans each of those days plus Wednesday.

In Rome, home heating is blamed along with heavy traffic for the eye-stinging, throat-irritating air. Until air quality improves, thermostat settings in Rome’s homes and office cannot exceed 18 degrees Celsius (64 degrees Fahrenheit.) The total hours a day furnaces can run is being reduced from 12 to eight. Schools and hospitals are the exceptions. But many Romans ignore the rules and leave the heat on all day.

Warm, dry weather is worsening pollution.