This disease is a mounting fever that eventually consumes its victims in fire. Those coming into contact with infected individuals, or the ash of the immolated victims must make a DC 13 Constitution saving throw or become infected. Creatures that do not breath receive advantage on this saving throw.

The first symptoms of the disease appear in 1d4 + 1 hours, as the infected begin to develop a heavy fever and rash. The infected creature suffers 1 level of exhaustion; while the infected creature has at least 1 level of exhaustion they are also vulnerable to cold damage. At the end of each long rest, the infected creature must make a DC 15 Constitution saving throw. On a failure, they take 2 (1d4) fire damage for each level of exhaustion they possess and gain another level of exhaustion. On a success, they take no damage and lose a level of exhaustion. If the creature reaches level 6 of exhaustion, they burst into bright flame and then become a pile of loose ash. All creatures within 10 feet of the dying creature must make a DC 14 Dexterity saving throw or take 27 (5d10) fire damage on a failed save, or half as much damage on a successful one. Once the infected creature loses all levels of exhaustion, the disease ends.