Overview
- Dr David Garley explains that the transition into sleep normally involves a 0.5°C–1.5°C drop in core body temperature, so being too hot or too cold can block sleep onset.
- Excessive cold can trigger brief ‘arousals’ that pull sleepers into lighter, less refreshing stages or cause awakenings, a pattern often noticed during early‑morning temperature drops.
- Winter respiratory illnesses and inflamed airways can make it harder to fall asleep, increase snoring, and may exacerbate obstructive sleep apnoea in susceptible people.
- Shorter daylight, reduced activity, and seasonal low mood can disrupt circadian rhythms and create a bidirectional loop in which poor sleep and anxiety or depression reinforce each other.
- Practical steps include keeping a consistent routine, staying active, using layered bedding, keeping the bedroom cool but not icy, getting daylight exposure, and avoiding forcing sleep when restless.