#DailyBloggingChallenge (20/25)
It is well documented that temperature difference before/after bedtime can aid with slumber/wakefulness, so either taking a hot or cold shower/bath would do the trick; all depending on the current room temperature and personal preference.
This is also the hypothesis of why so many cultures have adopted the practice of washing their faces instead of full body immersion into the temperature difference. Since this suffices enough to get similar effects.