A device for measuring body temperature comprising: a first surface for thermal engagement with a body a second surface substantially opposed to the first surface such that, in use when the first surface is engaged with a body, the second surface is exposed to a thermal environment of the body first and second temperature sensors encapsulated within a first material and a second material located between the first and second temperature sensors and intersecting a first axis passing substantially through the first and second sensors and the first and second surfaces the device being configured such that the net thermal conductivity across the device is greatest along the first axis and the second material having a volumetric heat capacity which substantially exceeds that of the first material.
