Sleep Hygiene: The Primary Care Foundation

A fixed wake time is the anchor the rest of the routine hangs off; the National Sleep Foundation and CDC both put consistent timing first.

Core body temperature has to drop for sleep onset, and a cool room is the easiest way to let that happen.

Light is the strongest signal to the circadian clock, so residual light delays and fragments sleep.

Intermittent noise causes arousals you often will not remember but that still cost you sleep quality.

The Sleep Foundation advises a minimum of eight hours, because caffeine's half-life leaves a meaningful dose in your system well into the evening.

Evening screen light and the engagement itself both delay sleep onset; the Sleep Foundation's concrete recommendation is the hour before bed.

Alcohol shortens sleep onset but fragments the second half of the night, and a large late meal adds reflux and discomfort.

Daytime activity improves sleep quality, while vigorous exercise too close to bedtime keeps core temperature and arousal elevated.

A 2024 systematic review in the Journal of Sleep Research found no fabric consistently superior, with wool and linen outperforming cotton in several trials, so the supported principle is thermal comfort and breathability rather than any one material. The source video was a paid Cotton Incorporated partnership and its cotton-specific claim is not independently supported.

This is stimulus control, a core component of CBT-I, the first-line treatment for chronic insomnia; it stops the bed becoming a cue for being awake and frustrated.