Temperature is the critical variable for dosimetry in thermotherapy.
It makes no sense to continue with this practice when today's technology affords us the means to measure temperature objectively and consistently. Temperature sensors and thermistor probes have been readily available for many decades. Furthermore, the present range of thermometric devices are affordable, compact, reliable and easy to use. There just doesn't seem to be any good excuse presently for not using these devices routinely in our clinical practice. The most obvious site to do this is at the interface between the modality and the patient, that is, the surface of the skin.