In IEEE Std 242-1986, there is a table named "Table 11 - 60 Hz Low-voltage Cable in Conduit - Resistance and Reactance Data for Insulation Types THWN and THHN in Milliohms per Conductor per 100 ft at 25 deg Celsius Copper Conductor"
We know that as per NEC, the temperature rating of THWN is 75...