This technical note presents a coupled thermo-hydro-mechanical model for unsaturated soil, which can be applied in the context of high temperature. A new pore gas or bulk air tranfer equation is introduced. Additionally the effect of temperature on the latent heat of vapourisation and specific heat capacities is incorporated. Adsorbed water is also included. The performance of the model is demonstrated via the simulation of a high temperature (150°C) therm-hydraulic-mechanical experiment carried out on a column of MX-80 bentonite by Commissariat à l'Energie Atomique, France. The model showed good correlation of experimental and numcerical results.