Chapter Three: The Case of the Missing Lifeguard - S3-E3
Question: Why did Doris Driscoll start eating fertilizer? Why fertilizer of all the materials?
Answer: Doris was being possessed by the mind flayer, and like the rats, they craved fertilizer.
Chosen answer: A single layer sleeveless top like Billy wears after his possession by the Mind Flayer would probably not make a big difference to his body temperature, but even if it did, it's possible he deliberately wore it to fight or hurt the creature invading his mind as he does later demonstrate some ability to keep it at bay.
Sierra1 ★
Billy did wear long-sleeved top after his possession. It was unlike him. I know he used to wear sleeveless top or didn't wear top at the pool before his possession. Your second answer makes sense, though. Thanks.
Bunch Son