Was a kid in high school waiting for the bus my wife and I would pass while she dropped me off at the el station in chicago. We both had people we knew when we were in high school who were like that. I swear the guy might put on a hat, scarf, and gloves but refuse to wear a jacket or lose the shorts.
Speaking as the "never wore winter clothes" kid, when you're overweight, you can tolerate colder weather due to body fat being a natural insulator
Combine that with a natural tolerance for cold, and sensory issues with heavy clothes, and you get this.
To the point where I had many fights with my parents over it
(I still wear sandals year round because fuck shoes)