The invention provides an electrically-driven kitchen machine including a food mixer or a food processor. The machine has a support platform for supporting a receptacle for foodstuffs to be mixed or otherwise processed. The machine has an electric motor used to drive mixing or processing tools disposed in the receptacle; and a heater for heating the foodstuffs in the receptacle. In order to ensure that the temperature of the foodstuffs is accurately determined, the base of the receptacle consists of multiple layers, including a first metallic material, such as aluminum, having a relatively high thermal conductivity, sandwiched between outer and inner skins of a second metallic material of lower thermal conductivity than the first metallic material. The machine is also provided with first and second probes, each protruding through the receptacle-supporting platform and urged upwardly to contact the inner skin and the first metallic material respectively. The second metallic material typically comprises stainless steel, and the heater typically comprises an induction heater, in which case the probes are constructed so as to resist absorption of heat from the energy field generated by the heater.