The evidence-based sleep hygiene checklist

Light

Light is the strongest signal your body clock receives. Get it in the morning, lose it at night.

• Get outside within an hour of waking — ten minutes of daylight, longer if it's overcast. Morning light sets the clock for the whole day.^[1]

• Evening light delays melatonin and pushes your clock later. Dim the lights for the last hour or two and switch evening lamps to warm bulbs (2700 K or lower).^[2]

• Screens off for the last hour — or at least night mode on and brightness down. Evening screen light delays melatonin and pushes your clock later.^[2]

• Sleep in a properly dark room: blackout blinds or a mask, and no standby LEDs.

Temperature

Your core temperature has to fall to start sleep. Everything here helps it do that.

• Keep the bedroom cool — around 18–19 °C (64–66 °F). Sleep depends on the core cooling down, and a warm room fights it.^[3]

• A warm shower or bath one to two hours before bed. The heat pulls blood to the skin and speeds the core cool-down that follows.^[4]

• Move during the day — regular exercise reliably improves sleep quality. If a hard session late in the evening leaves you wired, move it earlier.^[5]

Timing

Regularity does more than most people expect. Wake time anchors the clock more than bedtime does.

• Aim for 7–9 hours of sleep, and allow a little more time in bed than that. Both short and long sleep track with higher mortality; seven to nine is where the curve bottoms out.^[6][7]

• Same wake time every day, within 30 minutes.^[8]

• Keep weekend lie-ins under an hour. A shifted weekend schedule — 'social jet lag' — is linked with worse cardiometabolic markers.^[8]

• If you nap, keep it under 30 minutes and finish before 15:00.

Caffeine, alcohol and food

The three that people most underestimate — and the easiest to test with a week of logging.

• Caffeine curfew six hours before bed — earlier if you're sensitive. Taken six hours before bedtime, 400 mg of caffeine measurably cut total sleep. Decaf is not caffeine-free either.^[9]

• No alcohol as a sleep aid. It shortens the time to fall asleep, then fragments the second half of the night and suppresses REM.^[10]

• Finish large meals two to three hours before bed. A light snack is fine.

Seven-night sleep log

Change one thing from the list, then log a week. Rate how rested you feel from 1 (wrecked) to 5 (fully recovered).

How to use it

1. 1

   Tick what you already do. Most people are surprised how many boxes are empty in the light and caffeine groups.

2. 2

   Pick two or three items to change — not all fourteen. The ones you can test in a week are the best ones to start with.

3. 3

   Log seven nights. The 'rested' score matters more than the hours; it is what the other columns have to explain.

4. 4

   In Lamplit, the free sleep tracker keeps the same log without the pen — and with Pro, it imports nights automatically from Apple Health or Health Connect.

Common questions