There is a recognised but poorly understood association between hypothermia and acute pancreatitis. A histological study of the pancreas was made in eight patients with accidental hypothermia who had evidence of pancreatitis at necropsy. From an analysis of the patterns of parenchymal necrosis in the pancreas it was thought that there were at least three possible mechanisms for the relation between hypothermia and pancreatitis. Firstly, that ischaemic pancreatitis may result from the "microcirculatory shock" of hypothermia. Secondly, that both hypothermia and pancreatitis may be secondary to alcohol abuse: and finally, that severe pancreatitis may be the primary disease and that hypothermia results from the patients' social circumstances.