Fire Mode can be triggered by harnessing Fire energy. In Team Sonic's case, they could harness Fire energy after their Communicators absorbed some from a fissure. When utilizing Fire Mode, the users envelop themselves in a superheated fire-like aura. Anything they come into contact with are then instantly heated to above sub-zero temperatures. This effect can be channeled through weapons as well, like Amy's Hammer and Tails' Blaster. As a side-effect, the user constantly leaves a red and orange color trail.
Fire Mode is one of the core gimmicks in Sonic Boom: Fire & Ice. While Fire Mode is active, the player can turn solid ice blocks with fire icons that they or their attacks touch into intangible water blocks, enabling the player to pass through ice barricades. The player can as well light wicks to clear paths. To freeze and counteract the Fire, the player has Ice Mode. Otherwise, any thawed water will refreeze after a couple of seconds.
To use Fire Mode in gameplay, the player can simple toggle between it and Ice Mode using the L or R button. When Fire Mode is active, the Nintendo 3DS's lower screen will show burning flames around the lead character's icon.