This invention relates to a temperature sensor for body temperature measurements. The temperature sensor is made of several layers, where a first layer has a central heater embedded therein, a second layer which is attached to the first layer has at least one first thermistor embedded therein for measuring a first temperature value, a third layer has at one ore second thermistor embedded therein separated from the first thermistor for measuring at least one second temperature value, but this third layer is adapted to be in contact to the skin of the surface of the body for conducting the heat escaping from the body through the layers. The difference between the first and the second temperature values indicates the heat flux from the body. The heat emitted from central heater is tuned oppositely to the heat flux until a zero heat flux is reached, where the temperature at the at least one second thermistor at zero heat flux indicates the body temperature. These layers are fabric layers.
