Cooling properties of everyday liquids

Abstract

ObjectiveTo examine the cooling properties of a variety of ‘everyday’ hot liquids within the context of scald injuries in the United Kingdom. MethodsThe temperature of common hot liquids, including water, tea, coffee and various other liquids (i.e. takeaway coffees, “Indian tea”, chicken curries, hot milk and oil) were recorded over a time period, using digital cooking thermometers. ResultsMinimal difference was detected between the cooling rates of hot water, coffee and tea. Indian tea cooled at a slower rate. The speed at which milk cooled was less than other liquids and the higher the fat content the slower it cooled. Takeaway beverages had a lower starting temperature and retained heat for substantially longer periods. The assessment of cooking oil revealed intense heat production and prolonged cooling. ConclusionThe authors propose that if a patient is exposed to a ‘common’ scalding agent that has been cooling for 10min or less then the temperature of that fluid is likely to be greater than 60°C and therefore capable of causing a burn within seconds of exposure. Furthermore, most liquids tested take between 15 and 30min to reach a “safe temperature” below 53°C.