¶ Cold Therapy (Cold Exposure)

Cold therapy includes cold showers, cold plunges, and cold water immersion. It is used for perceived benefits such as improved mood, reduced soreness, and “resilience” — but it also carries real safety risks, especially with sudden immersion and in people with cardiovascular disease.

Safety first

Cold water immersion can trigger a cold shock response (rapid breathing, heart rate and blood pressure spikes) and can be dangerous — especially for people with cardiac history or uncontrolled hypertension.^[1]

¶ What People Use It For (Common Goals)

Acute mood boost / alertness
Perceived recovery and reduced soreness
“Stress resilience” (hormetic framing)
Metabolic interest (brown fat activation; evidence varies)

¶ What to Track

Primary (acute): mood, energy, perceived soreness, sleep quality
Secondary: training performance trends, resting HR trend, HRV trend (if used)
Safety: symptoms (dizziness, chest pain, palpitations, severe headache) → stop immediately

¶ Practical Parameters (Rule of Thumb)

There is no single consensus protocol. If you experiment:

Start warmer and shorter, and adapt gradually.
Avoid breath-holding or risky immersion conditions.

¶ Risks and Contraindications (Examples)

Cardiac disease history, arrhythmias, uncontrolled hypertension: avoid or seek medical guidance first.^[1:1]
Risk of drowning due to gasp reflex and hyperventilation in cold shock.^[1:2]
Hypothermia risk with longer exposure.

¶ References

American Heart Association. You’re not a polar bear: The plunge into cold water comes with risks. 2022. https://www.heart.org/en/news/2022/12/09/youre-not-a-polar-bear-the-plunge-into-cold-water-comes-with-risks ↩︎ ↩︎ ↩︎