Climate Change Impact on Sleep Patterns

Climate Change Is A Public Health Issue If night time room temperature of 24 degC is the threshold for comfortable sleep, no wonder we increasingly need aircon to sleep well. It's not because people are becoming soft or too used to aircon. Aircon is really becoming a necessity for long term health reasons. In Singapore’s 3rd National Climate Change Study, it is mentioned that: "More warm nights where temperatures exceed 26.3 degrees Celsius are also projected. From an average of 76 nights per year in the last 40 years, Singapore could experience such warm nights most nights in the year by end century." https://lnkd.in/g4m_9RQh And this is using a threshold of 26.3 degC that is significantly higher than the WHO recommendation of 24 degC. At 24 degC, I suspect many (most?) nights in Singapore are already above the threshold. Also, official temperature measurements by the Met Service try to eliminate the urban heat island effect, so the actual temperature in a housing estate could well be higher than the official MSS figures. Which brings me to my favourite topic of using wearable cooling suits or cooling blankets instead of aircon. Let's try to cool the person, not the room. "High night time temperatures can become dangerous if they prevent the human body from cooling off and recovering from daytime heat. The World Health Organisation (WHO) recommends keeping room temperature at or below 24 deg C during the night – a threshold above which sleep can be uncomfortable. This is especially important for vulnerable people, such as babies, the elderly and people with chronic health conditions, according to the WHO. Around 2.4 billion people experienced at least two additional weeks on average per year over the past decade when the thermometer didn’t fall below 25 deg C at night, it found." "Long-term historical data being patchy or missing for many countries, researchers decided to compare their findings with an imaginary world where the only thing that has changed is the amount of carbon in the atmosphere. The Caribbean nation of Trinidad and Tobago experienced the largest increase of any country, with an extra 47 nights per year above 25 deg C. The Indian city of Mumbai endured an additional two months of hot nights. The 25 deg C threshold “isn’t some hard-and-fast number below which health is fine and above which health is harmed,” Dr Obradovich, who was not involved in the analysis, explained." "Several studies have shown that nocturnal temperatures above 25 deg C deteriorate the quality and length of sleep –- which is vital for humans to function – and increase the risks of strokes, cardiovascular conditions and mortality. The elderly and people on lower-income are disproportionally affected, researchers previously found." https://lnkd.in/guE8QQQK

Everyone knows rising temperatures make it harder to sleep. What remains largely unspoken is how repeated hot nights alter personality over time. Janabai Sonawane had never argued or bickered with her closest friends. She is 62, a farm worker, and until last year, no one would have called her short-tempered. The summer of 2025 saw night temperatures increase significantly in her village. She was struggling to fall asleep as heat lingered inside her tin-roofed home well past midnight. After 8 hours of backbreaking work in extreme heat and more labour at home, she would lie down by 10 p.m. and in minutes, drift off to sleep. But those nights of restful sleep are now a distant dream. Soaring temperatures and humidity make her sweat through the night. Only by 3 a.m. did the temperature drop marginally to become bearable. By 5 in the morning, she is up again, fetching water, cooking, preparing for another day. Weeks of broken sleep became months. Sleep is not restful, and she often snaps at her family, and then regrets it. “People think I’m angry all the time. But I just don’t have the strength [to be genial] anymore.” Time with her friends, laughing and chatting, listening and helping each other, sharing stories, is now a thing of the past. Months of poor sleep, irritability, and fatigue, make her avoid social interactions for days; she prefers to keep to herself, foregoing the friendship she once happily enjoyed. “When the room’s ambient temperature is high, it becomes difficult for the body’s internal thermoregulation system to lower the core body temperature enough to start and sustain sleep,” explains Dr. Uvais Nalakath Arakkal. Over time, that loss of rest alters mood, cardiovascular health, and social relationships. Across parts of India, people are experiencing up to 80 hot nights with temperatures over 25°C. That’s a lot of warm nights to get through in the year. Read my story for People's Archive of Rural India to understand what climate-driven sleep loss is doing to mental health. The story has also been translated into 14 languages! Link in comments: 

Hot Nights, Restless Sleep: How Rising Temperatures Can Disrupt Rest As summer temperatures rise, many people are feeling the heat – literally - when it comes to sleep. And it’s not just discomfort. It’s biology. Our bodies need a slight drop in core temperature to initiate and maintain sleep. But hotter nights can disrupt that process - leading to fragmented sleep, reduced deep sleep, and next-day fatigue. 📊 A 2024 study published in Economics & Human Biology found that nighttime temperatures above 25°C (77°F) were associated with measurable decreases in sleep time, compared to cooler nights in the 5–10°C range. Increased temperatures have also been associated with an increase in apnea events. Sleep health is not just a personal habit - but a public health priority. Sleep loss linked has been associated with: ✅ Increased cardiovascular strain ✅Impaired cognitive performance ✅Mood volatility 💡 So what can we do? ➡️ Keep your bedroom temperature between 65–68°F (18–20°C). This ideal temperature range can be ambitious. So it's important to make your sleep environment as cool as reasonably possible, and to maximize those things that are potentially easier to control, like darkness and distractions. ➡️Use light, breathable bedding and blackout shades to reduce retained heat ➡️Avoid exercise or large meals in the 2–3 hours before bedtime ➡️Stay hydrated, but limit fluid intake 1 hour before bed At Resmed, we’re committed to helping people sleep well in every environment - with solutions that adapt to individual needs and support healthier lives. Is the heat affecting your sleep this summer? How are you adapting? #SleepHealth #CircadianRhythm #RestAndRecovery #PublicHealth #Resmed #SummertimeSleep