#. General Considerations As mentioned in the biology section, HT is defined as elevation of temperatures to a supraphysiologic range. Typically this is in the range of 40℃ to 45℃ with heating durations of 1 hour. Much higher temperatures, in the range of 50℃ to 100℃ for a few minutes, have been used in single-treatment thermal ablative procedures for a variety of clinical sites, most often for ..