Fire is a common hazard in the canon/fanon series of Pikmin. Fire hazards are usually in the form of fiery geysers spouting from the ground (or, uncommonly, on walls). These geysers can be destroyed with any type of Pikmin. However, if Pikmin not immune to fire hazards touch the fire, they burst into flames and run around, dying after a few seconds. Still, they can be saved if whistled at. Red Pikmin are completely immune to this hazard whatsoever.
Several enemies also utilize fire as a weapon, for instance, the Fiery Blowhog breathes fire from its snout. Some enemies also use fire as a defensive covering, like the Fiery Bulblax. Red Pikmin, due to their immunity, generally should be used against fire-wielding enemies/hazards.
Pikmin: Attack of the Breadbugs
Fire can be found mainly in the Inferno Territory of the Land of Wonders. Examples of enemies that use this hazard are Fiery Breadbugs and the Toasty Breadbug. Fire can also be found around the Inferno Territory naturally.