I was exploring heat conduction between body parts and noticed some technical oddities:
1. If you set a hand to 10249 U, which is hot enough to melt the fat but not enough to cause heatdam or ignition, the heat will conduct to the fingers and the lower arm, and is sufficient to cause death via blood loss. The temperature of the hand slowly drops as the heat moves to the other body parts. If you had set the hand to 10180 U instead, the dwarf would live with only hand fat melting.
2. If you set the hand on fire (10509 U), the entire body starts to heat up rapidly because the tile the dwarf is standing in is set to 10500-10700 U, and this heat can conduct to every exposed body part. Violating conservation of energy, the tile doesn't decrease in temperature as it provides heat to the dwarf's body parts. However, being underwater prevents the tile from being set to above ambient temperature and puts out active fires. If you get out of the water and a body part is still above the ignition temperature, you catch fire again.
3. If you set a wood gauntlet on fire, and then wear it, the part of your body that heats up the fastest is your teeth, followed closely by your skull, joints, brain, other internal organs, and ribs. The actual head and other fleshy body parts are slow to heat. The tile that you are standing in is at 10600 U or so, and is causing the heating. The hand that is wearing the flaming gauntlet is the same temperature as the hand that is not wearing anything. Very soon, you achieve fatal near-simultaneous full-body fat melting and bleeding.
I can only conclude that dwarf sweat is 150 proof alcohol. Getting a single drop of magma on a toe will kill a dwarf, whereas IRL it will be at worst the loss of a single toe. Any ‼object‼ will fill its tile with a cloud of incredible flame.