The invention concerns a temperature control device (10) comprising a heat pump (12) including a main refrigerant circuit (14) drawing calories from a cold source (16) to transfer them to a hot source (18), the cold source (16) including a refrigerant/air heat exchanger (26), called first evaporator. The cold source (16) also comprises a refrigerant/coolant heat exchanger (20), called second evaporator (28), thermally communicating the main refrigerant circuit (14) with a secondary coolant circuit (38) capable of being connected to at least a first secondary heat-exchanger circuit (42, 44) in heat exchanging relationship with a first source of calories of the vehicle. The first (26) and second (28) evaporators are connected in parallel.