A fire vortex is generated when a flame enclosed in a metal mesh is rotated. Rotation is attained by placing the setup on a rotating platform. The mesh serves to provide a circulating air current due to shear forces on its surface. This current then causes the flame to rotate; convection in this rotating air current then causes the flame to rise. One can demonstrate that this vortex is due to the rotating air current and not only convection by rotating the flame without the mesh around it. No circulating air current will arise since there are no shear forces, and thus no vortex will appear.

The circulating air current is analogous to the air currents in forest fires that provide angular momentum to the flames at the floor of a forest, causing the fire vortices to arise and reach the canopy, facilitating the spread of the fire. The demo can also be used when discussing cyclones and torados, though their similarity is mostly in the angular momentum given by air currents; the phenomena are completely different, though.