It's hard to dress right for school in the fall.
Mornings are usually cold and foggy, but it gets warm.
A week ago it was hot, good for local vintners, but too much for me. Humans are warm-blooded. We produce heat like a car engine, and we need active cooling from air and sweat. A hot tub feels great for a while, but only for a while. NASA apparently lost the Mars Climate Orbiter spacecraft due to another problem converting units.