The development and evaluation of a data acquisition system employing a hot/cold-wire probe for the simultaneous measurement of instantaneous velocity and temperature in the boundary layer of a non-isothermal turbulent flow is described. The performance of an analytical expression for compensating the velocity reading of a hot-wire for varying fluid temperature has been assessed using a simple, low cost, high performance thermal calibration unit. The effectiveness of the expression for compensation of a temperature contaminated hot-wire velocity reading in flows ranging from 0.75 to 8.5 m/s and temperatures between 20 and 60 degrees C has been demonstrated. For velocities in excess of 3 m/s the applied correction proved accurate to within +/-2.2% overthe 20-60 degrees C temperature range.