From D&D Wiki
Devil chills is a horrible disease that very few have ever survived. Usually caused by an encounter with some form of demonic outsider, devil chills acts so quickly; there is little chance of the victim surviving.
In its first stage, the victim is afflicted with a deadly fever and boils up and down their back. In the second stage, the victim begins to feel as if standing in a pool of ice water. In the final stage of the disease, the victim’s vital organs begin to shut down as they begin to bleed out of every orifice.
The affected creature takes 1d8+2 points of damage and must succeed on a DC 16 Fortitude save or be infected with the devil chills (incubation period 1d4 days, damage 1d4 Str.) Damage is dealt each day until the afflicted creature succeeds on 3 consecutive Fortitude saves, the disease is cured by magic, or the creature dies. The save DC is constitution-based.