Until you have experienced driving a race car for 2 hour stints in double layer fire proof everything, helmet, gloves, in August in 100+F with 90% humidity, on a track with another 100 idiots, you'll just have to imagine it.

I've done that in high summer kart races, they are usually only about 15 minutes duration , but the g forces were higher than in car races that I've done . A one hour enduro kart race on a bumpy track was hard on my back rather than my stomach.