Is It Better to Sleep With the Heating On or Off?

On a cold evening, leaving the heating on all night can feel like the obvious route to a comfortable bedroom. Yet anyone who has woken feeling hot, dry or restless may wonder whether a cooler room would be better. So, is it better to sleep with the heating on or off?

For many healthy adults, the best answer is to keep the bedroom comfortably cool and avoid heating it more than necessary. That might mean turning the heating off after warming the room, or using a thermostat, timer or low overnight setting so the temperature does not fall too far. The important question is not simply whether the boiler is on. It is what temperature the bedroom actually reaches while you sleep.

A slightly cool bedroom is generally more sleep-friendly than an overheated one, but a room should not be allowed to become uncomfortably or dangerously cold. These three points offer a starting place:

• Healthy adults often sleep well in a cool room: NHS sleep advice recommends a bedroom that is cool, dark and quiet, although personal comfort still matters.
• Heating may be sensible when the room becomes too cold: UK cold-weather guidance gives particular importance to temperatures of at least 18°C for people aged 65 or over, those with reduced mobility and people with health conditions such as heart or lung disease.
• Babies need separate guidance: The Lullaby Trust recommends a room temperature of 16–20°C for babies, together with suitable lightweight bedding or a well-fitting baby sleep bag and regular checks for overheating.

The practical answer, then, is usually off or turned down if the room stays comfortable; thermostatically controlled if it does not. Measuring the temperature is far more reliable than guessing from how the room felt at bedtime.

Temperature and sleep are closely connected. Core body temperature follows a daily rhythm and begins to fall around the period when we normally prepare for sleep. Research reviews describe thermoregulation as an important part of falling asleep and maintaining sleep, although the relationship involves the temperature of the skin, bedding and surrounding air rather than one perfect thermostat number.

The aim is a comfortable sleep microclimate: cooler air around the bed, with enough insulation from sleepwear and bedding to keep the body pleasantly warm. This is why a cooler bedroom and a suitable duvet can feel more restful than hot air combined with bedding that is too heavy.

Turning the heating off can work well when your bedroom holds its temperature and your bedding is right for the season. In a modern, insulated home, residual warmth may last through most of the night. If the room remains comfortable, continuing to heat it may simply leave you too warm.

It can also be useful to warm the bedroom before bed, then programme the heating to switch off or move to a lower setting. This creates a welcoming room when you change and settle down without necessarily maintaining the same daytime temperature until morning.

If you frequently wake cold, see a very low reading on the room thermometer or belong to a group more vulnerable to cold, a low thermostatic setting may be the more appropriate choice. The goal is not to prove that you can sleep without heating; it is to create a stable and comfortable environment.

Leaving the heating available overnight does not have to mean running radiators at full temperature. A programmed thermostat can call for heat only when the room or heating zone drops below its set point. This distinction matters because controlled background heating is very different from keeping the bedroom hot all night.

Overnight heating may be worth considering when:

1. the bedroom regularly falls below a comfortable temperature;
2. someone in the home is older, has reduced mobility or has a relevant health condition;
3. a baby sleeps in the room and it is difficult to maintain the recommended range;
4. the home is particularly draughty or poorly insulated; or
5. cold surfaces and inadequate ventilation are contributing to persistent condensation.

If you have a medical condition affected by temperature, follow advice from your healthcare team rather than relying on a general sleep guideline. Similarly, tenants dealing with inadequate heating, damp or mould should report the underlying problem instead of being expected to manage it solely by changing bedtime habits.

There is no single temperature that guarantees better sleep for every adult. NHS guidance focuses on making the bedroom comfortable, cool and neither excessively hot nor cold. Some UK sleep resources use about 17–18°C as a practical reference, but bedding, nightwear, humidity, age and personal preference all influence how that temperature feels.

Government-aligned cold-weather advice provides a health-focused threshold rather than a universal sleep optimum. The Met Office advises heating the home to at least 18°C, especially for people aged 65 or over, those with reduced mobility and people with health conditions. It notes that healthy, active adults under 65 wearing appropriate clothing may be comfortable slightly below 18°C.

For older people or those with pre-existing health conditions, a bedroom temperature of at least 18°C overnight may be beneficial. This is an important exception to casual advice that everyone should turn the heating off or sleep in a very cold room.

The Lullaby Trust recommends keeping rooms where babies sleep between 16°C and 20°C. A room thermometer is helpful because it is difficult to judge temperature accurately by touch alone. Check whether a baby feels hot or sweaty at the chest or back of the neck; hands and feet normally feel cooler and are not a reliable guide.

Avoid trying to compensate for a cold room by adding excessive bedding. Use suitable sleepwear and follow safer-sleep guidance for blankets or a correctly fitted baby sleep bag. Babies should not wear hats indoors while sleeping, and their heads should remain uncovered. If you are uncertain about dressing a baby for the room temperature, seek current guidance rather than improvising extra layers.

A very warm bedroom may make it harder to become comfortable, particularly beneath an insulating duvet. University Hospital Southampton's sleep-hygiene guidance notes that a very warm room is more likely to disrupt sleep, while the NHS suggests adjusting the temperature or safely opening a window when a room needs cooling.

Before lowering the temperature dramatically, check the whole bed. A high-tog duvet, heat-retaining mattress topper, thick protector and heavy sleepwear can create an overly warm microclimate even when the room itself is reasonable. Changing one layer may solve the problem more comfortably than opening a window wide in winter.

A persistently cold bedroom can also create colder walls, windows and corners. Moisture produced by breathing, showering, cooking and drying laundry may condense on these surfaces if it cannot escape. Government guidance identifies building defects, inadequate ventilation and inadequate heating systems among the factors that can contribute to condensation, damp and mould.

Heating alone is not a complete mould solution. Ventilation, insulation, leaks and other building problems must also be addressed. Keep trickle vents or appropriate ventilation working, use extractor fans in kitchens and bathrooms, and report recurring damp or mould to a landlord or qualified professional. Simply opening a bedroom window all night while the room becomes very cold may not resolve the underlying issue.

Start with a simple room thermometer placed away from a radiator, window or direct sunlight. Check it at bedtime and again when you wake, or use a device that records the overnight minimum. This shows whether your bedroom stays relatively stable or drops sharply before morning.

Thermostatic radiator valves can help manage individual rooms where the heating system supports them. A programmable or smart thermostat may also allow a lower night setting and a short period of warmth before waking. Follow the manufacturer's guidance and use a qualified heating professional if controls are confusing or not working correctly.

If the bedroom feels cold only when you first get into bed, focus on the bed rather than overheating the entire room. Breathable pyjamas, socks or an appropriate seasonal duvet can provide local warmth. Layering is useful because one blanket can be removed more easily than a very heavy duvet can be adjusted.

Tog is a measure of thermal insulation, not weight or quality. A higher-tog duvet retains more warmth; a lower-tog option generally feels cooler. The right choice depends on the season, the bedroom and how warmly you naturally sleep.

An adaptable duvet made from separate layers can be particularly practical in a British climate. The lighter section can be used in warmer weather, the thicker section during cooler periods and both layers together when additional insulation is needed. Natural fibres and breathable constructions may also help manage moisture, although no material removes the need to choose an appropriate warmth level.

Central heating controlled by a maintained system is not the same as using a portable heater beside the bed. The London Fire Brigade advises keeping portable heaters well away from bedding, curtains, furniture and clothes, and never using them to dry laundry. Some gas, solid-fuel and paraffin heaters also present a carbon-monoxide risk and require an appropriate alarm.

Rather than making a permanent decision based on the weather outside, treat bedroom temperature as something to observe and adjust. Measure the room, review the bed and then choose the lowest heating setting that keeps the sleeper safely comfortable.

For most healthy adults, sleeping in a comfortably cool room is preferable to keeping the heating high throughout the night. In a home that retains warmth, turning it off after bedtime may work perfectly well. In a colder property, or for someone more vulnerable to low temperatures, thermostatically controlled overnight heating can be the safer and more comfortable option.

The best answer is therefore not simply “on” or “off”. Use the actual bedroom temperature, your health needs and the way you feel on waking as your guide. With a sensible thermostat setting and bedding that suits the season, you can create a room that feels fresh enough for sleep without becoming uncomfortably cold.