Cold exposure and Sleep architecture
Each entry’s own grades, side by side. A grade says how strong the evidence is for one outcome — it does not rank one entry over the other.
Compound or practice
Cold exposure
Real alertness and mood effects, honest recovery trade-offs — and much smaller metabolic claims than the internet says.
Grade C4 graded outcomesrevised Jun 10, 2026
A hand-written entry in Prometheus's bundled library. Its grades are the entry's own reading of the evidence, not a peer-reviewed review.
Compound or practice
Sleep architecture
The recovery system everything else compounds on — deep and REM timing matter more than raw hours.
Grade A4 graded outcomesrevised Jun 28, 2026
A hand-written entry in Prometheus's bundled library. Its grades are the entry's own reading of the evidence, not a peer-reviewed review.
Graded in both
Outcomes are matched by name. Two entries can describe the same outcome in different words, so one listed further down may still be graded in the other.
No outcome has the same name in both entries. They may still overlap under different wording — read the two lists below.
Graded only in Cold exposure
- Alertness / mood (acute) Moderate effectEvidence grade B
- Perceived soreness (endurance) Small effectEvidence grade B
- Hypertrophy interference (post-lifting) Moderate effectEvidence grade B
- Fat loss / metabolism Trivial effectEvidence grade D
Graded only in Sleep architecture
- Insomnia severity (CBT-I components) Large effectEvidence grade A
- Deep-sleep minutes (schedule consistency) Moderate effectEvidence grade A
- Next-day cognition Moderate effectEvidence grade A
- REM cost of evening alcohol Moderate effectEvidence grade A
Conditions
- DepressionCold exposure: May improveEvidence grade CSleep architecture: ImprovesEvidence grade B
Only in Cold exposure
- Raynaud's syndrome WorsensEvidence grade B
- Cardiovascular disease May worsenEvidence grade C
- Metabolic syndrome May improveEvidence grade D
Only in Sleep architecture
- Insomnia ImprovesEvidence grade A
- Hypertension ImprovesEvidence grade B
- Type 2 diabetes ImprovesEvidence grade B
What each entry says about the other
- Cold exposure’s entry · Watch with: Evening immersion is arousing — keep it before mid-afternoon
- Sleep architecture’s entry · Watch with: Evening immersion is arousing — morning slots only
Both columns are read from the entries as they stand in this library. A comparison is not advice to take either one, and it is no substitute for a clinician who knows the person.