Nothing, people did nothing, these things aren’t life threatening. So in order to survive them you just need to wait till it’s over.

There is this one case discussed in the YouTube video from almost 70 years ago where it is claimed the temperature got up to 60 degrees C. But all of the events in past 30 years with proper data haven’t gotten above 40C, so I would very much doubt the 60C figure. These events are also brief, lasting at most a few hours. They are also rare and can only happen in specific places.