In operation results of numerical researches of the heat transfer processes are rendered in «the measured environment — the surface thermoelectric transformer» system. By means of the developed model of heat transfer research of influence on results of measurements of value of air gap between the thermocouple and a body surface is estimated (body temperature is measured). It is shown that the air gap value has an essential impact on the necessary duration of heating of a sensitive element (minimum time of measurements). Maximum permissible magnitues of these gaps values for the measurements in real practice are set. Experiments to assess the numerical research results adequacy of are made.