Native Americans of the Central United States practised ‘egg curing’, a traditional treatment that probably originated in Europe. To diagnose an illness, the egg was broken and rubbed over the bare skin of a patient, the ‘curer’ diagnosing the malady from any usual form or colour of the yolk and albumen. Alternatively, often to relieve a fever, an unbroken egg was rubbed on the skin to absorb the heat and then buried in a stream.