This paper investigates the thermal and fluid dynamic effects of a cold air jet generated by a Ranque-Hilsch vortex tube on the cutting tool of a milling machine. A simulation model that predicts the temperature field and the displacements of the tool due to the thermal effects was developed. Such a model can help to correct machining errors and improve cutting accuracy of air-cooled milling machines. Experimental results validated the model. Eventually, the post-processing of the computational fluid dynamics (CFD) data has been conducted in virtual reality.