Should Your Blanket Change When the Aircon Goes to 25°C?

Probably, yes. The lab studies on duvets point the same way: the warmer your room, the lighter and more breathable your cover needs to be, and the comfortable zone inside your bed is narrow, roughly 30 to 33°C. If you raise the aircon to 25°C to save power, as Singapore's Go 25 movement encourages, the quickest fix for a stuffy night is usually the blanket, not the remote.

Why 25°C is the new default

Singapore launched Go 25 in May 2025 to get homes, offices and buildings to set air-conditioning at 25°C or higher. The government's announcement cited a study with Ngee Ann Polytechnic that found energy savings of up to 12% for each degree raised from 23°C to 25°C in offices, with no reported increase in discomfort. Fans are part of the plan.

The advice has reached the bedroom too. A May 2026 CNA Lifestyle piece, produced in partnership with an aircon maker, suggested setting 25°C with a fan before bed rather than running 22°C all night, and using sleep or econ mode.

Plenty of people don't use aircon at night at all. Early results from the HEATS study, reported by The Straits Times in June 2026, found Singapore bedrooms averaged 28.4°C at night across 150 residents, with roughly a third using aircon, a third mixing it with fans, and a third using none.

So the question for a lot of sleepers is no longer "what should the room be?" It is "what should I put on top of me at 25°C, or 28°C?"

What the duvet studies found

Most of this research comes from sleep chambers in China and Denmark, so the rooms were cooler than a typical Singapore night. The patterns still travel.

| Study | Who or what | Key finding | |---|---|---| | Yan et al., Journal of Thermal Biology, 2023 | 12 adults, whole nights, six duvets | Heavier, warmer duvets widened the range of comfortable room temperatures. Comfort held when the bed climate stayed around 30 to 33°C | | Zheng et al., Indoor Air, 2022 | 16 adults, down, silk and polyester quilts at six fill weights | Comfortable room limits rose and fell in a straight line with quilt insulation. At the same insulation, silk tolerated the warmest rooms, then down, then polyester | | Bivolarova et al., CLIMA 2019 | Thermal manikin, 15 and 20°C, 50% and 70% humidity | A 1,100 g polyester quilt insulated less than a 600 g down quilt. Doubling a quilt's weight did not double its insulation | | Zhai et al., SSRN preprint | 10 adults, 26°C and 50% humidity | Deep sleep ranked crepe, then silk, then synthetic quilt, matching how comfortable people felt. Humidity at the waist was linked with deep sleep |

The bed climate is the target

The 2023 study is the clearest. With the warmest duvet, people were comfortable in rooms from 8.2 to 17.7°C. With the lightest one, the range was 16.4 to 22.2°C. In both cases, sleep quality held up as long as the air between body and cover stayed around 30 to 33°C. The 2022 study landed in a similar place, with comfortable bedding temperatures of about 31 to 33°C.

One practical takeaway follows from those numbers. Even the lightest duvet in the 2023 study had a comfort ceiling of 22.2°C. At 25°C with aircon, or 28°C without it, a typical duvet is likely to push your bed climate above that 30 to 33°C zone. That is an inference from cooler-climate labs, not a Singapore trial, but it fits what many people here already do: kick the cover off at 3am.

Weight and warmth are not the same thing

The Danish manikin test is a useful reminder that a heavier cover is not automatically a warmer one. Fill type and how the quilt is stitched together mattered as much as grams. A heavy synthetic quilt let more heat escape than a lighter down one, and doubling weight did not double the insulation.

That matters for anyone who likes the pressure of a weighted blanket but sleeps warm. The weight gives the pressure. The warmth depends more on fabric, fill and how well heat and moisture can escape.

Humidity is the other half

The small preprint from a 26°C, 50% humidity room is not peer reviewed yet, and 10 people is a small sample. Still, it points at something Singapore sleepers know well: damp skin under a cover feels worse than a warm room. The best-performing quilts in that test were the more breathable ones. We covered the airflow side of this in our piece on fans in humid heat.

How to match your cover to your room

These are starting points, not rules. Bodies differ, and so do bedrooms.

1. Check your setpoint first. If you've moved from 22°C to 25°C, expect to need less on top of you. Swap a thick duvet for a light quilt or a single breathable layer.
2. Think in layers, not one heavy cover. Two thin layers let you drop one when the aircon timer switches off and the room warms up. Our look at whether the top sheet is pointless goes into that.
3. Pick breathable fabrics for warm rooms. In the lab work, natural, airier fills such as silk and crepe did better in warmer conditions than dense synthetics.
4. Use a fan with 25°C. Moving air helps sweat evaporate, which is exactly what a humid bed struggles to do.
5. Separate pressure from heat. If you want the calm of a weighted blanket at 25°C, choose one built to shed heat rather than trap it. A cooling weighted blanket like the one on our specifications page is one option. Any weighted blanket in breathable fabric, used in a well-ventilated room, follows the same logic.
6. Watch for clues. Waking sweaty, kicking off covers or sleeping better on the sofa under the fan all suggest your bed climate is running hot.

If you're sleeping badly most nights even after adjusting your room and bedding, or you wake gasping or snore loudly, talk to a doctor. Persistent insomnia and possible sleep apnoea deserve a proper check.

Sources

1. Yan F, Zheng Q, Ke Y. Effect of quilt thermal resistance on bedding system and sleep thermal comfort. Journal of Thermal Biology. 2023;117:103713. https://doi.org/10.1016/j.jtherbio.2023.103713
2. Zheng Q, Yan F, Wang H, Ke Y. Effects of quilts on comfortable indoor temperatures and human thermal responses during sleep. Indoor Air. 2022;32(9):e13122. https://doi.org/10.1111/ina.13122
3. Bivolarova M, Melikov A, Snaselova T, Shen C. Passive control of the bed micro-environment by quilts. E3S Web of Conferences (CLIMA 2019). 2019;111:02064. https://doi.org/10.1051/e3sconf/201911102064
4. Zhai R, Xu J, Shi T, Song H, Chen B, Lu Y. Is it possible to indicate the sleep quality of people in an air-conditioned room by thermal and moisture comfort of quilt? SSRN preprint. https://papers.ssrn.com/sol3/papers.cfm?abstract_id=5350759
5. Ministry of Sustainability and the Environment, Singapore. Launch of Go 25 National Movement. 16 May 2025. https://www.mse.gov.sg/latest-news/launch-of-go25-national-movement/
6. Khoo BK. Your air-con could be costing you more than you think, here's how to use it better. CNA Lifestyle, in partnership with Daikin Airconditioning (Singapore). 28 May 2026. https://cnalifestyle.channelnewsasia.com/living/smarter-aircon-use-save-money-energy-583496
7. Begum S. What's the average night-time temperature in S'pore bedrooms? A muggy 28 deg C, says new study. The Straits Times. 25 June 2026. https://www.straitstimes.com/singapore/environment/whats-the-temperature-in-the-bedroom-in-spore-a-muggy-28-deg-c-says-new-study-on-residents