A warm shower and a to-do list do more for sleep than a nightcap

Key takeaways

• In a review of 17 studies by University of Texas researchers, a warm bath or shower 1 to 2 hours before bed was linked to falling asleep sooner, with as little as 10 minutes in the water¹.
• In a Baylor University sleep-lab study of 57 young adults, people who spent five minutes writing a to-do list before bed fell asleep in about 15 minutes, versus about 25 for people who wrote about finished tasks³⁵.
• A 2025 review of 27 studies found that alcohol before bed delayed and shortened REM sleep, the dream-rich stage, and sped up falling asleep only at high doses⁷.
• A Cochrane review of 13 trials found that relaxing music at bedtime improved how well people with sleep problems felt they slept, though brain-wave recordings showed no change in how fast they fell asleep⁹.
• An evening routine is a good habit, not a treatment: sleep-hygiene advice alone does little for chronic insomnia, so trouble that keeps going calls for a clinician¹¹¹³.

On weeknights in Baylor University’s sleep lab, 57 college students took turns climbing into bed at 10:30, wired with sensors that track brain waves³. Before the lights went out, each one spent five minutes writing³.

Chance decided what they wrote: half listed what they had to get done over the next few days, and the other half wrote about tasks they had already finished³⁴.

The to-do writers fell asleep faster, in about 15 minutes compared with about 25⁵. And the more specific their lists, the faster they drifted off⁴.

That’s one small study, but it captures something many people sense: the last hour of the day sets up the night. A few evening habits now have research behind them. Others, including the classic nightcap, look worse the closer scientists look.

Below, we look at what the evidence shows, a 60-minute wind-down you can adjust, and the things to skip late in the evening.

A warm bath works by helping your body cool down

It sounds backward, but to fall asleep, your core body temperature needs to drop a little. A warm bath seems to speed that drop.

In 2019, biomedical engineers at the University of Texas at Austin, led by Shahab Haghayegh, published a review in the journal Sleep Medicine Reviews¹². They screened 5,322 papers and found 17 studies that fit, 13 of them with data they could combine¹.

The pattern was clear enough to act on. Water at about 104 to 109°F (40 to 42.5°C) was linked to better self-rated sleep and better sleep efficiency, meaning more of the time in bed was spent asleep¹. Timed 1 to 2 hours before bed, as little as 10 minutes in the water went with falling asleep sooner¹. The abstract gives no number of minutes, but CNN reported that bathers fell asleep about 10 minutes sooner on average².

The likely reason: warm water draws blood to your hands and feet. That helps your body shed heat, so your core temperature can fall¹. A federal sleep guide from the National Heart, Lung, and Blood Institute (NHLBI) makes the same point: your temperature drops after a hot bath, and that can make you sleepy¹².

Timing matters. In the CNN account, a bath only 15 minutes before bed came too late to deliver the same benefit².

Keep the caveats in view, though. The authors called the research scarce and said the best timing and length still aren’t settled¹. CNN also reported that the team was using the data to develop a prototype water bed meant to help regulate body temperature². A possible future product is worth knowing about when you weigh any study.

A shower counts, since the review covered both showers and baths¹. If you have heart disease, low blood pressure or trouble with balance, ask your clinician whether very warm water is safe for you, and use a nonslip mat.

Five minutes with a to-do list can quiet the “don’t forget” loop

Worry about unfinished tasks is a big part of why people lie awake, Michael Scullin’s Baylor team noted⁴. The question was whether writing about the future would stir that worry up or settle it³.

Writing seemed to settle it: the to-do group fell asleep significantly faster⁴. Sleep was measured with polysomnography, the brain-wave recording used in sleep clinics³.

Detail made a difference: people who wrote more thorough, specific to-do lists fell asleep faster. Among people writing about finished tasks, more detail went the other way⁴⁵.

The study had clear limits. All 57 people were healthy adults aged 18 to 30 with no sleep problems, and there was no group that skipped writing altogether, so it can’t say whether the to-do list helped or the “done” list hurt⁴⁵.

Scullin said the results might not apply to people with insomnia and called for a larger study³. The work was funded partly by the National Institutes of Health and the Sleep Research Society Foundation³.

Still, it’s free and takes five minutes, and specific beats vague. “Call the dentist at 9 to move Thursday’s cleaning” gives your brain a clear handoff. “Life stuff” doesn’t.

A nightcap helps less than you think, and it costs you REM sleep

Plenty of people pour a drink to unwind at night, and the research on what that does to sleep has sharpened in the past few years.

In 2013, Irshaad Ebrahim of the London Sleep Centre and colleagues reviewed 20 studies of healthy people⁸. At every dose, alcohol helped people fall asleep sooner and sleep more solidly in the first half of the night⁸. Then the pattern flipped: sleep grew more broken in the second half, and the first bout of REM sleep, the stage when most vivid dreams happen, came later⁸.

A larger 2025 review led by Carissa Gardiner and Shona Halson of Australian Catholic University pooled 27 studies of healthy adults⁷. On average, alcohol pushed back the first REM period by 18 minutes and cut total REM by about 11 minutes⁷.

The surprise was about falling asleep. Pooled across studies, alcohol shaved only about 2 minutes off the time it took, a gap too small to rule out chance⁷. A clear effect showed up only at high doses, about 0.85 grams of alcohol per kilogram of body weight⁷.

REM felt the alcohol much sooner. The first REM period was delayed from about 0.35 grams per kilogram, and total REM fell from about 0.5⁷. The authors count a drink as 10 grams of alcohol for a 137-pound (62-kilogram) adult. By that math, the REM delay began around two drinks, REM loss around two to three, and faster sleep onset around five⁷.

Why do the two reviews differ? The older one described how most studies came out. The newer one pooled the numbers in a meta-analysis and tracked dose, a method better suited to sizing small effects⁷⁸. The newer team’s verdict was plain: using alcohol as a sleep aid isn’t an appropriate strategy⁷.

The 2025 review had its own limits. Of the 27 studies, 21 carried some risk of bias, and nearly all gave the drinks within about three hours of bed, so it couldn’t say whether an early glass with dinner matters less⁷. The authors reported no conflicts of interest⁷.

The NHLBI guide adds a practical warning: alcohol tends to wake you partway through the night as it wears off¹². The CDC advises skipping alcohol close to bedtime¹⁵.

If you rely on a drink every night to fall asleep, tell your clinician, because that’s a problem worth solving directly.

Music helped people feel rested, but brain recordings were less sure

Music is one of the oldest bedtime tools, from lullabies on.

In 2022, a Cochrane review by K.V. Jespersen and colleagues pooled 13 trials with 1,007 adults who had insomnia symptoms, aged 18 to 83⁹. People listened to recorded music daily, for an average of about 36 minutes a session, for three days to three months⁹.

Listeners rated their sleep quality better than people who didn’t listen, and the reviewers rated that evidence moderate in certainty⁹. The trials used calm music such as classical, new age and jazz¹⁰. Music picked by the researchers worked about as well as music participants chose from a set list¹⁰.

The twist: in the three trials that measured sleep with brain-wave recordings, music didn’t change how fast people fell asleep or how long they slept⁹. Every trial had a high risk of bias in at least one area, partly because you can’t hide from someone that they’re hearing music¹⁰. No harms were reported⁹.

So music may help most with how a night feels, and that still counts. A calm playlist with a sleep timer is cheap, safe and pleasant.

A routine is a cue for sleep, not a cure for insomnia

Many traditions close the day with ritual: washing up, a prayer, a cup of tea, a few lines in a journal. These habits fit natural-health values because they’re drug-free, they cost little and they put you in charge.

The research supports some specific pieces of that ritual, but it also draws a line. In its 2021 guideline on behavioral treatments, the American Academy of Sleep Medicine (AASM) advised against using sleep-hygiene advice alone to treat chronic insomnia¹¹.

Sleep hygiene means lists of good habits, like keeping a cool, dark room and avoiding caffeine late in the day. On its own, the guideline found, that kind of advice was minimally effective¹¹.

The approach with the best evidence is cognitive behavioral therapy for insomnia, or CBT-I, a structured program usually delivered over four to eight sessions¹¹. It’s also drug-free, and our upcoming insomnia article covers it in depth.

So think of your evening routine as a signal rather than a treatment. Done most nights, it tells your body and mind that sleep is coming. If you still can’t sleep, more steps won’t fix it.

Build a 60-minute wind-down that fits your evening

This plan is our own design, built from the studies above, and it hasn’t been tested as a package. Pick the steps that suit you, and count back from your lights-out time.

Time before lights out	Step	Options	Why
60 to 90 minutes	Warm bath or shower, 10 minutes or more	Water around 104 to 109°F if comfortable; a warm shower works too	Linked to falling asleep sooner when done 1 to 2 hours before bed1
45 minutes	Set up tomorrow, then write a to-do list for 5 minutes	Paper by your keys or bag; one line per task, with a time	More specific lists went with faster sleep onset4
40 minutes	Dim the lights and put screens away	Lamps instead of overhead lights; phone on its charger in another room	NHLBI lists bright lights and screens among bedroom distractions12; the CDC says to turn devices off at least 30 minutes before bed, the AASM 30 to 601415
30 minutes	Something calm	Relaxing music on a timer, a paper book, gentle stretching, prayer or quiet reflection	Music improved self-rated sleep quality9; NHLBI suggests reading or music as part of a bedtime ritual12
5 minutes	Bathroom, then bed	Small sip of water if needed, not a big glass	Too much fluid late can mean bathroom trips at night12
0	Lights out	Cool, dark, quiet room	The CDC advises a quiet, relaxing, cool bedroom15

Short on time? Try the 20-minute version: a warm shower, five minutes of list writing and a calm song or two. Shift it earlier if you can, since the bath works best well before bed¹².

Our sibling articles cover the other pieces. For relaxation, breathing and meditation, see our upcoming relaxation articles. For children’s bedtime routines, see our article on busy parents.

What the evidence says, rated

Evening habit	What studies found	Evidence level
Warm bath or shower 1 to 2 hours before bed	Faster sleep onset and better self-rated sleep across 17 studies; authors call research scarce1	Promising but early
Five-minute to-do list at bedtime	One lab study of 57 healthy young adults; no no-writing group45	Promising but early
Relaxing music at bedtime	Better self-rated sleep quality in 10 trials (moderate certainty); no change in 3 small brain-wave studies; all trials at high risk of bias in some way910	Promising but early (better for how sleep feels than for measured sleep)
A nightcap helps you sleep	Delays and cuts REM; faster sleep onset only at high doses78	Evidence says no, or unsafe
Sleep-hygiene tips alone treat chronic insomnia	Minimally effective in the AASM guideline review11	Evidence says no, or unsafe (the claim failed; no safety issue)
An elaborate routine works better than a simple one	We found no trials comparing them	Not enough evidence

When an evening routine isn’t enough

See a clinician if signs of a sleep problem show up three or more nights a week, or if trouble sleeping keeps going, NHLBI advises¹². Insomnia counts as chronic when it happens three or more nights a week for three months or longer, according to NHLBI⁶. Signs of a possible sleep disorder include:

• regularly taking more than 30 minutes to fall asleep, or waking and struggling to get back to sleep¹³;
• loud snoring, snorting, gasping or pauses in breathing that a bed partner notices¹³;
• feeling very sleepy during the day, or dozing off at the wrong times¹³;
• creeping or tingling feelings in your legs in the evening that ease when you move¹³;
• abnormal behaviors during sleep, or arms and legs that jerk often while you sleep¹³¹⁴.

Drowsy driving is an emergency of its own. Trouble keeping your eyes open, constant yawning or not remembering the last few miles mean you’re too sleepy to drive safely¹². Pull over somewhere safe.

If poor sleep comes with hopelessness or thoughts of harming yourself, call or text 988 any time. Our upcoming articles on insomnia, sleep apnea, restless legs and when to get a sleep evaluation go deeper.

Questions readers ask

The bottom line

The best-supported evening habits are simple. A warm bath or shower an hour or two before bed helps your body cool toward sleep, and a short, specific to-do list may hand off the worries that keep your mind running. Calm music can make a night feel better, even if it doesn’t change the brain-wave numbers.

A nightcap, on the other hand, trades a small head start for a choppier, REM-poor night. Treat your routine as a signal, keep it light enough to do most nights, and see a clinician if sleep trouble keeps coming back.

Related reading

• Blue light gets the blame, but time on screens may cost more sleep
• Moving can ease anxiety, though viral shaking and somatic workouts are less proven
• Reflux responds to habits, and acid pills are safer than headlines say
• Busy parents need a few anchors more than a perfect routine
• Sleep trackers count your hours well, but their sleep stages are rough guesses

Sources

1. Haghayegh S, Khoshnevis S, Smolensky MH, Diller KR, Castriotta RJ. “Before-bedtime passive body heating by warm shower or bath to improve sleep: A systematic review and meta-analysis.” Sleep Medicine Reviews, 2019;46:124-135 (EM-Consulte abstract). em-consulte.com
2. CNN. “A hot bath 1 or 2 hours before bedtime can significantly improve your sleep, researchers say.” Republished by KSL.com, July 31, 2019. ksl.com
3. Baylor University. “Can Writing Your ‘To-Do’s’ Help You to Doze? Baylor Study Suggests Jotting Down Tasks Can Speed the Trip to Dreamland.” Baylor Media and Public Relations, January 11, 2018. news.web.baylor.edu
4. Scullin MK, Krueger ML, Ballard HK, Pruett N, Bliwise DL. “The effects of bedtime writing on difficulty falling asleep: A polysomnographic study comparing to-do lists and completed activity lists.” Journal of Experimental Psychology: General, 2018;147(1):139-146 (Emory University repository record). open.library.emory.edu
5. British Psychological Society Research Digest. “Researchers say this 5-minute technique could help you fall asleep more quickly.” BPS, 2018. bps.org.uk
6. National Heart, Lung, and Blood Institute. “Insomnia: Diagnosis.” NIH, accessed October 2026. nhlbi.nih.gov
7. Gardiner C, Weakley J, Burke LM, Roach GD, Sargent C, Maniar N, Huynh M, Miller DJ, Townshend A, Halson SL. “The effect of alcohol on subsequent sleep in healthy adults: A systematic review and meta-analysis.” Sleep Medicine Reviews, 2025;80:102030 (open-access copy, Australian Catholic University). acuresearchbank.acu.edu.au
8. Alcoholism: Clinical & Experimental Research. “Alcohol and sleep” (news release on Ebrahim IO, Shapiro CM, Williams AJ, Fenwick PB, “Alcohol and Sleep I: Effects on Normal Sleep,” 2013). ScienceDaily, January 23, 2013. sciencedaily.com
9. Arnold MJ. “Listening to Music for Insomnia” (Cochrane for Clinicians, on Jespersen KV, et al., Cochrane Database of Systematic Reviews, 2022, CD010459). American Family Physician, May 2023. aafp.org
10. Cochrane New Zealand. “Does listening to music help adults who suffer from insomnia?” PEARLS No. 708, August 2022. nz.cochrane.org
11. Arnold MJ. “Behavioral and Psychological Treatments for Chronic Insomnia Disorder: Updated Guidelines From the American Academy of Sleep Medicine.” American Family Physician, 2022;105(1):97-98 (on the AASM guideline, Journal of Clinical Sleep Medicine, 2021;17(2):255-262). aafp.org
12. National Heart, Lung, and Blood Institute. “Your Guide to Healthy Sleep.” NIH Publication No. 11-5271, revised August 2011. nhlbi.nih.gov
13. MedlinePlus. “Sleep Disorders.” National Library of Medicine, updated December 4, 2025. medlineplus.gov
14. Robards K. “FAQs of Zzz’s: Answering your top 10 sleep questions.” Sleep Education, American Academy of Sleep Medicine, March 15, 2024. sleepeducation.org
15. Centers for Disease Control and Prevention. “About Sleep.” CDC, updated May 15, 2024. cdc.gov