Flame infantry are equipped with a flamethrower as their main weapon. They can dish decent damage to anything, be it infantry, vehicles, or buildings if they are close enough to the target. Any infantry struck by the flamethrower will continue to be damaged by burning.
They sport fire-resistant suits, making them resilient to stolen flame tanks. However, this does not make them any more resistant to the chemical sprayer. They are also equipped with a backup pistol and a timed C4 for armor and building destruction.