FIELD: construction. SUBSTANCE: method and device for its implementation relate to construction and can be used to control temperature of monolithic concrete in monolithic and prefabricated monolithic ceilings of buildings during its maintenance. Protection device of surface of formwork against wind and stagnation of air masses when monitoring temperature of monolithic concrete in the floor at its maintenance is made in form of hollow truncated cone with support projections. A handle-holder is rigidly fixed on the side of the smaller base. Control method involves periodic determination of air temperature and outer surface of formwork by means of pyrometer with subsequent periodic calculation of temperature of hardening concrete. To the cleaned surface of the formwork the device is pressed. It is held and at least twice in a row the surface temperature is determined, the area of which is limited by the area of the larger base of the device using an infrared thermometer. EFFECT: improving measurement accuracy of external surface temperature of formwork.