ARGANIL, PORTUGAL (REUTERS) - Portuguese firefighter Vitor Hugo captured a 'firenado' on Oct 7 in the central province of Arganil, Portugal.

Known as a 'fire devil' or 'fire whirl', this phenomenon is a whirlwind induced by a fire and often made up of flame or ash.

They usually start with a whirl of wind or smoke.

At least 36 people have died in wildfires raging through parched farmlands and forests in Portugal.