By Mel Moss, Founder of Minó · 6 min read
When Louis was waking repeatedly through the night, I did what most parents do. I looked at the routine. Earlier bedtime, more consistent timing, less screen exposure before bed. All reasonable things. None of them fixed it.
It was not until I started looking at the research on paediatric sleep that I understood what was actually happening. Temperature dysregulation is the most common cause of night waking in children. Not noise. Not light. Not the wrong routine. Temperature.
Once I understood the mechanism, everything else started to make sense.
How temperature and sleep are connected
Sleep is not just a state the brain switches into. It is a physiological process that requires the body to lower its core temperature. When core body temperature drops, the brain interprets it as a signal to initiate sleep. This is why we naturally feel sleepy in the evening — the body is cooling down as part of its circadian rhythm.
When core temperature rises during sleep — even slightly — the brain registers it as a disruption. It triggers a partial arousal. The child surfaces from deep sleep. If conditions feel different from when they fell asleep, they wake fully.
This is not just about room temperature. What a child is wearing, what they are sleeping under, how active they were before bed, and what they ate all affect how their body holds heat overnight. Room temperature is one variable in a much more complex system.
The room your child fell asleep in at 7pm may feel very different to their body at 2am. That gap is where night waking happens.
Why children are more vulnerable than adults
Adults have a mature thermoregulatory system. When we overheat, we sweat efficiently, blood flow to the skin increases, and our body corrects course — usually without waking us up.
Children’s thermoregulatory systems are still developing. They heat up faster than adults and cool down slower. They have a smaller body surface area relative to their mass, which makes self-correction harder. A child sleeping under the wrong weight of bedding cannot adjust the way an adult would. They just wake up. This remains measurably different from adult thermoregulation well into middle childhood — not just in infancy.
Research published in Frontiers in Psychiatry found that thermal comfort during sleep is influenced not just by room temperature but by the microclimate of the bed itself — the interaction between bedding and the child’s body. A room at the right temperature does not guarantee a comfortable bed microclimate. The bedding is doing its own work, independently of the thermostat.
The role of sleep cycles
Understanding why temperature causes night waking also requires understanding how children cycle through sleep.
Children’s sleep cycles are shorter than adults’ — around 50 minutes in younger children, gradually lengthening with age. At the end of every cycle, the brain briefly surfaces into a lighter state before dropping back under. In that moment, the brain runs an unconscious check: is everything the same as when I fell asleep?
If the answer is no — the room has warmed, the bedding has become heavy and uncomfortable, the fabric is now damp — the child wakes fully. This is why a child can fall asleep easily and still wake repeatedly through the night. Getting to sleep and staying asleep are two different problems with two different solutions.
The room at 3am needs to match the room at 7pm. Temperature stability across the full night is not a comfort preference. It is a physiological requirement.
What you can actually control
Room temperature is the variable most parents focus on, and it does matter. Most sleep experts recommend a room temperature of between 18 and 20 degrees Celsius for children — slightly warmer than the adult recommendation of 16 to 18 degrees, because children’s bodies lose heat more quickly.
But room temperature is only part of the picture. The bedding itself matters just as much. Synthetic fills trap heat and create a warm, static microclimate around the body. Natural fibres — wool, alpaca, linen-cotton blends — regulate temperature actively, adapting as body heat fluctuates through the night. They breathe. They wick moisture. They maintain a more stable microclimate without any intervention required.
Fabric weight matters too. A too-heavy duvet in a bedroom that cools in the early hours, or a too-light one in a room that stays warm, creates the conditions for repeated waking. The right weight for the season and the room is a genuinely useful thing to get right.
Clothing plays a role as well. A child who is dressed too warmly for bed and then sleeping under a heavy duvet has limited options for self-regulating. Natural, breathable sleepwear — and an awareness that children do not always need as many layers as adults assume — is part of the same system.
The test most parents find useful
If you check on your child during the night and the back of their neck feels warm and damp, they are overheating. That is the most reliable indicator — not the room temperature, not how many layers seem appropriate, but the actual state of their skin. A neck that feels cool and dry is the goal.
Night waking is exhausting, and it is easy to keep looking at routines and behaviour when the answer might be simpler than that. If everything else is consistent and your child still wakes, start with temperature. Start with what they are sleeping under. The research points there more often than anywhere else.
