In normal conditions the rate of cooling of body is

Algor mois (Latin Algor: coolness, mois: death) or the chill of death is the cooling of the body that normally takes place after death, where the body temperature equilibrates with its environmental temperature. For temperate countries, Marshal and Hoare formula is used. The rates of fall of temperature in an average built person is 1degF upto 3 h, 2degF upto 9 h and 1.5degF up to 12 h. The rule of thumb is that the temperature falls at about 1.5degF/h. Ref - Krishan Vij textbook of forensic medicine and toxicology 5e pg : 79