He went to bed at the same time every night, turned off digital devices an hour before bed, and before turning in, took a hot shower. He then tracked his sleep on his smartwatch for a month. He noted his heart rate, time in bed, time asleep, quality of sleep, and percentage of deep sleep. Why the hot shower? Recent sleep science found that participants who used water-based passive body heating—also known as a bath—before bed slept sooner, longer, and better.
