Great question — answering as the UphillTech team:
Echoing my answer on another stack... The DVD commentary for Episode III (with producer Rick McCallum ) explains this in more detail. In short, the blue haze you see is not only a repulsor field but it also creates a form of cooling for the Jedi: Rick McCallum : This blue light around the bottom of the light and the platforms was added later on, in Production. George felt that at one point, that we needed to feel that there was some cooling effect, some kind of shield...a reason why our actors aren't burning up being around this intense heat so Roger Guyett and his team added these shields, this shield generator into this shots as another pass after they'd completed a lot of these...
Full answer by user7812: https://movies.stackexchange.com/a/45231 (CC BY-SA 4.0).
Need it done for your business? UphillTech.
