In one embodiment, a method generally comprises monitoring real-time electrical data at Power Sourcing Equipment (PSE) transmitting power over a cable to a Powered Device (PD), calculating thermal characteristics for the cable based on the monitored data, and periodically updating the thermal characteristics based on the monitored data. The power comprises multi-phase pulse power, the data comprises voltage and current measured for each phase of the multi-phase pulse power, and the voltage is greater than 60 volts at the PSE.