Burning

Meaning You're On Fire
Caused By Pyro's Weapons
Damage Varies
Cure Water, Medic
Lasts for 15 Seconds

This happens when you are either shot by the Pyros flamethrower, incendiary cannon or walk through fire from a napalm granade or touch a burning teammate. The damage varies depending on whether you stay in range of the source or get away. While you are on fire, in addition to losing health, you see great sheets of flae on front of you - this makes it very hard for certain classes, ie Sniper, to shoot straight and can be pretty disconcerting. You have the choice of just ignoring it and waiting for it to stop, or, if you have low health, of having a quick swim - that'll put you out.