How hot is aurora?

A quick google search for "aurora plasma temperature" brings up several interesting results, which seem fond of reporting temperatures in electron volts. That's entirely sensible, but probably not quite what you want. While we could do some math to convert those measurements to Kelvin, Rocket measurements of plasma densities and temperatures in visual aurora by A. G. McNamara, however, conveniently reports temperatures in Kelvin already. According to that source, the temperature of the electron plasma in an aurora ranges from 500 K to 1400 K. Note, however, that the density, and therefore the total heat capacity, of the plasma is very low; the altitude at which auroras occur is practically outer space. So, if you somehow managed to fly up there and stick your hand in one, it probably wouldn't feel all that warm.