Research

Hormonal

Creating a warm microclimate around the skin (31-35°C) via bedding or nesting behavior initiates NREM sleep by triggering distal vasodilation and activating preoptic hypothalamic circuits that link warmth to body cooling.

To improve sleep onset, focus on creating a warm skin microclimate (31-35°C) using appropriate bedding rather than just lowering room temperature. This warmth triggers vasodilation in hands and feet, which signals the brain to initiate NREM sleep and body cooling. If you struggle with sleep latency, ensure your bedding allows you to maintain this specific skin temperature range.

GoodSupportsHIGH confidence
In optimal room temperatures, approximately 19–21◦C, we attempt to establish skin microclimates between 31 and 35◦C and deviation from this range has a negative influence on sleep... This warming persists through the night to maintain a sleep-permissive state that also permits selective vasodilation in NREM... We hypothesised that thermoregulatory circuits themselves might have an important role in facilitating sleep... external warmth is a permissive state for NREM initiation.
Edward C. Harding et al. · Frontiers in Neuroscience · 2019

Why this rating

The paper is a review citing multiple human observational studies, animal lesion studies, and optogenetic experiments, providing strong mechanistic evidence.

Source

The Temperature Dependence of Sleep

Edward C. Harding et al. · Frontiers in Neuroscience · 2019

DOI 10.3389/fnins.2019.00336

narrative_reviewCited 243×
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DOI resolved against Crossref · corpus check 2026-06-10

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