Bryan Johnson· Author
Sleep in a well ventilated cool bedroom, with temperature around 20°C
Loading…
The evidence is convergent. Multiple independent sources reach the same conclusion, the underlying mechanism is well-characterized, and even the field's most cautious voices treat it as worth doing.
Sleep in a well ventilated cool bedroom, with temperature around 20°C
Every Sunday: the week’s new conflicts and verdict changes — and nothing else.
Native comments, Twitter mentions, and Reddit threads about this claim — surfaced together so the conversation isn't fragmented across platforms.
Bookmarking — the dossier-vs-overview split is the right call. Most of the time I want overview; sometimes I want receipts.
Would love a "what would change this verdict" RSS feed. Sign me up if it exists.
This aligns with WHO and European recommendations to keep bedroom temperatures above 18°C or 20°C.
Aim for a bedroom temperature between 19-21°C (66-70°F).
your body needs to cool down for you to be in the right place to go to sleep and if you're too hot you're not going to be able to fall asleep
10 minutes of bright outdoor light within the first hour of waking anchors the circadian phase and improves sleep onset that night.
Morning sunlight exposure shifts the cortisol awakening response forward, improving daytime alertness.
Long-term morning sunlight reduces age-related macular degeneration risk.
Sleep regularity predicts all-cause mortality more strongly than sleep duration.
Tracking deep sleep on a wearable accurately reflects EEG-measured slow-wave sleep.
Caffeine has a half-life long enough that consumption after 2pm measurably degrades deep sleep in slow metabolizers.