Hafnium carbide HfC (at%: 42%C; 49%Hf; 7%O) was investigated under rapid heating by a current pulse, in a time of 5-8 mu s. The temperature was measured by radiance of a flat surface of a carbide plate (thickness 130 microns) at a given emissivity. This carbide plate was clamped between two K-8 plates, to prevent evaporation of the carbide and to prevent surface discharge at high voltage along the sample. Input specific energy (enthalpy), melting heat, solidus and liquidus temperatures (4000-4200 K), electrical resistance and heat capacity for solid and liquid states were measured up to 5000 K.