The dive reflex, which slows heart rate and constricts blood vessels, is triggered by facial immersion in cold water, mimicking the physiological responses seen in diving.

Experiencing discomfort through practices like cold plunges can help us build resilience and learn to navigate stress more effectively.

Cold showers post-training do not significantly hinder training effects compared to full cold water immersion, providing some mental benefits without the same metabolic effects.

Deliberate cold exposure, such as cold showers or ice baths, offers distinct benefits compared to other self-imposed stressors due to the immediate onset of stress it creates.

Avoid cold immersion, such as ice baths, within four hours after training sessions aimed at endurance, hypertrophy, or strength, as the inflammation from these workouts is crucial for adaptation. Cold water immersion reduces inflammation and can hinder progress.

To wake up effectively, increase your core body temperature quickly by taking a cold shower or ice bath for one to three minutes.

A drop in body temperature is essential for falling and staying asleep, and can be accelerated by taking hot baths or showers before bed.

Heat should be approached gradually, as our neurons measure it in absolute terms, making it safer and more comfortable to find a personal threshold.

To safely use deliberate cold exposure for hangover recovery, aim for one to three minutes in cold water, which can spike adrenaline and dopamine levels.