Dear Dr. Mo: Is sauna really healthy and should I go there when I have a flu?
Dear reader: When you are in most saunas, its dry heat, which can become as high as 85° C (in some saunas, even higher), can have some intense effects on the body.
Your skin temperature spikes to about 40° C within minutes. The average person will pour out a half a liter of sweat during a short stay in a sauna.
The heart rate jumps by 30% or more, allowing the heart to approximately double the amount of blood it pumps out each minute (its minute volume).
Stress hormones ACTH and Cortisol rise substantially while Adrenalin and Noradrenaline are reduced; other changes in hormonal balances happen as well.
These effects (vigorous sweating, increased heart rate and hormonal changes) are similar to those induced by a moderate exercise, which is why saunas could be so appealing.Circulation patterns change while in sauna and most of the extra blood flow is directed to the skin, which becomes reddish; the circulation actually diverts blood away from the internal organs.
Blood pressure in saunas is always unpredictable, rising in some people but falling in others, which might be a health risk for some people with blood pressure problems. Saunas generally should not be considered as a therapeutic approach to hyper or hypotension – visit your doctor first.
Saunas are generally safe to use. Beyond some effects of relaxation and vasodilatation, there is still little evidence to show that saunas have any other health benefits although many are being claimed and under research (rheumatic pain, mild depression, chronic pain etc.)
In addition, people with uncontrolled or poorly controlled heart disease or blood pressure would be better off to avoid heating up in a sauna.
On the other hand, patients with stable and controlled heart disease should be ok with moderate sauna use and could even get some mild benefits out of it (potentially improves arrhythmias and improves vasodilatation).
To further answer your question – do not take a sauna when you are ill (flu or otherwise), and if you feel unwell during your sauna, get out immediately.
Some evidence shows that regular sauna may reduce incidence of common cold but more research is needed to substantiate these results.
Here are a few simple rules to follow in order to be safe in a sauna:
- Stay in for no more than 15–20 minutes;
- Before and after your sauna, avoid alcohol and medications that may impair sweating and cause overheating; in addition, alcohol dehydrates you further putting you at greater risk of overheating;
- Cool down gradually after sauna – do not jump into a swimming pool to cool off (I have seen people do this dangerous practice);
- Drink two to four glasses of water after each sauna to replenish your fluids and help to cool off.
Saunas could be an addition to general well-being activities – be aware of your health and use saunas in moderation.
Yours in health,