Cold Plunge — 3 min at 11 °C
Three minutes to the shoulders in 10–12 °C water, 2–3x/week, triggers a norepinephrine release that sharpens alertness for hours.
Submerge up to the shoulders in 10–12 °C water for three minutes, two or three times per week, to trigger a large norepinephrine release that sharpens alertness for hours. Over weeks it improves cold tolerance and mood scores — start with shorter exposures and build up.
The protocol
- Duration: 3 min.
- Frequency: 2–3x/week.
- Water temp: 10–12 °C.
- Prerequisites: never alone, exit immediately if hyperventilating, never combine with alcohol.
What you get
- Sharpened alertness for hours afterward.
- A norepinephrine surge.
- Improved cold tolerance over weeks.
- Better mood scores.
Contraindications
- Cardiovascular disease.
- Raynaud syndrome.
- Pregnancy.
- Cold urticaria.
- Recent meal.
Evidence level
Medium. There is reasonable supporting evidence for a norepinephrine response and subjective alertness and mood effects; cold exposure carries real cardiovascular risk, so honour the contraindications.
Related protocols
Sources
AgeGen never invents studies and never recommends prescription drugs by brand. Biohacks are experiments, not prescriptions — honour the contraindications and talk to a clinician if a condition above applies to you.