The Pompeii worm lives on the chimneys of deep-sea hydrothermal vents with its tail bathed in 80°C water and its head in 22°C water, the steepest thermal gradient any animal on Earth tolerates, and it survives by farming a fleece of bacteria on its back that may be insulating it from the heat
Alvinella pompejana lives on hydrothermal vent chimneys with its tail near 80°C and head at 22°C — the steepest thermal gradient tolerated by any known animal — and wears a fleece of chemosynthetic bacteria that may insulate it from the heat.