Fire damage is Aggravated and ignores armor; it may be soaked only with Fortitude in the case of Vampires (shapeshifters and other beings that can naturally soak aggravated damage can do so as normal). A fire's size determines the levels of aggravated damage a character endures per turn, while its heat determines the difficulty of the soak roll. A character suffers the full damage effect for each turn that she's in contact with the flames; she must leave the area and/or put out any fire on her to stop taking damage. All damage inflicted by fire is automatically successful unless soaked (i.e. a character trapped in a bonfire takes two automatic health levels of damage per turn, not the results of two damage dice per turn).
Heat of Fire
Heat of a candle (first-degree burns)
Heat of a torch (second-degree burns)
Heat of a Bunsen burner (third-degree burns)
Heat of an electrical fire
Heat of a chemical fire
Size of Fire
Torch; a part of the body is exposed to flame
Bonfire; half of the body is exposed to flame
Raging inferno; entire body is engulfed in flame
Electricity in and of itself does not cause aggravated damage, but the heat generated by lightning or high-voltage electrical current can cause internal burns which are aggravated. Electrical damage may be soaked normally, using a character's Stamina (plus Fortitude for vampires). Damage is considered "normal" damage unless the character botches her soak roll, in which case the injury is considered aggravated as a result of internal burns.
If your character falls to Maimed (5 Health Levels of damage), she is scarred temporarily by the flames (reduce Appearance by one until her wounds recover to Bruised). If she is reduced to Crippled (6 Health Levels) or Incapacitated (7 Health Levels) by the fire, the burns cover the majority of her body, reducing Appearance by two.