AS if tornadoes aren't dangerous enough, Some of them Can actually be made of fire. When a wildfire reaches very high temperatures,it Causes the air to become hot and to rise. Cooler air rushes in to replace the hot air. This Creates Strong winds. These winds Suck Up burning plants and even the fire itself. When this happens. like it did On March 14, 2014, in Denver, Colorado, U.S.A., a tornado of fire is produced. This tornado Can become 15 meters (50 feet) wide and grow as tall as a 40-story building.