Are cold showers and saunas worth doing for your nervous system?

Dan HarrisJournalist and author · former ABC News anchor · no clinical, research or teaching credential claimed

Probably worth the 15 seconds, with the mechanism story held loosely

What it rests onHe finishes his daily shower with 15 seconds of cold after interviewing a vagus nerve researcher, is building towards 30 to 60 seconds, and links a Harvard Health summary plus a paper on facial cold contact. In the same post he writes the caveat himself: these practices 'may help regulate the nervous system in the moment; whether they literally increase vagal tone over time is a harder scientific question.'

Andrea LovePhD · immunologist and microbiologist

The cold and heat literature does not support the claims made for it, and cold immersion carries real risk

What it rests onHer argument: the cold plunge studies conflict (one study of 10 athletes found a small white cell rise, another found nothing, a Dutch randomised trial found 30 percent fewer sickness absences but no reduction in days feeling unwell); sudden immersion below 60F can kill in under a minute; the usually cited sauna study had 20 male participants aged 20 to 25 and a population likely confounded by income, diet and exercise.