I have randomly come across about five different sites talking about fire tornadoes in the last week. Apparently, there was one in Brazil earlier this week.
Fire tornadoes, also known as fire devils or fire whirls, occur when a strong wind whips a brush fire into a whirlwind. They are typically 30-200 feet (10-50m) tall and a few metres wide and last only a few minutes. The largest fire tornadoes can be half a mile high with winds of 100 miles per hour and can last up to 20 minutes.*
In 1923, the combination of the fires from the great Kanto earthquake and the high winds from a developing typhoon resulted in a fire tornado that killed 38,000 people in 15 minutes.
*More information here.