A thermal sensor (20) located in the centre of a food simulant composition (24) linked to a remote measuring indicating and/or regulating device (28). The temperature of the food simulant changes in the same way as food stored in its vicinity and is unaffected by the movement of the ambient air which varies in temperature dramatically. This allows an actual reading and recording of stored food temperature and the regulation of the temperature within a refrigerated space by a thermostat (16). Its uses are mainly for frozen, chilled and refrigerated food, and the reading of temperature of food cooked for example in micro-wave ovens.