From typicallyspanish.com

Costa del Sol
Ten residents have a lucky escape in Periana
By h.b.
Apr 30, 2007 - 3:31 PM

Ten residents of a block in the Málaga village of Periana had to be treated for Carbon Monoxide poisoning on Sunday night.

It seems the gas came from a badly ventilated heater in one of the homes in the building.

Despite the concern all the patients were treated in situ and the local fire service declared the situation under control an hour later.