Acoustic Thermometry is capable of phenomenal accuracy, but it is a difficult technique to apply in many practical situations. Here we describe a modification of the technique, which permits robust temperature measurements to be made, potentially with milli-kelvin resolution, over a temperature range extending from cryogenic temperatures to over 1000 °C.The technique uses measurements of the time-of-flight of acoustic pulses in tubes usually filled with an inert gas such as argon. The tubes - typically made of stainless steel with an outer diameter of 6 mm - act as acoustic waveguides and can be several metres long and bent into complex shapes. The time-of-flight reflects the average temperature along the entire length of the tube. Local temperature information can be inferred in several ways. Typically a second shorter tube is used and the difference in time-of-flight reflects the temperature in the region at the end of the first tube. If the measurement length is sufficiently long - typically 1 metre of tube - then a measurement resolution of less than 1 mK is achievable.The technique is well suited to measurements in harsh environments in which conventional sensors degrade. We show results from early tests, which highlight the strengths and weaknesses of the technique.