If you are unsure about your overall health, then you should check with your physician before taking one. If you are new to the sauna experience, then you should take shorter saunas at lower temperatures to condition your body to the high temperatures. Below are some basic precautions one should consider before using the sauna.
The risk of dehydration, leading to heat stroke in more sensitive individuals, exists and can be reduced by maintaining hydration before, during and after the sauna. It is important to drink only water when one is hydrating oneself, be careful when drinking caffeinated drinks, sweet drinks and alcoholic beverages as they have a tendency to dehydrate the body. Ones electrolyte balance is contingent upon the balance of sodium, potassium, calcium and magnesium; for more detailed information see Wikipedia on Electrolytes. If you have any medical conditions, especially high blood pressure and/or heart disease, then be sure to check with your physician first before using a sauna.
As stated above, alcohol dehydrates the body and using the sauna would dehydrate the body more through perspiration. In addition, being under the influence of drugs or alcohol negatively affects ones judgement. Persons with low blood pressure or heart disease should be cautious. The heat of the sauna causes capillaries in the skin to dilate that in turn lowers blood pressure, the heartbeat then increases to keep blood pressure normal. Be aware and pay attention to how you feel before and after a sauna. Persons with high blood pressure should also be cautious. Interestingly, in Finland high blood pressure is fairly common, because of high alcohol consumption, and the sauna is enjoyed by everyone without incident.
Most pregnant women who are used to taking saunas should have no problem enjoying them, but use lower temperatures and do not stay in as long. Women in Finland take saunas throughout their pregnancy, in the old days babies were born in the sauna because it was the most sterile environment. Children should be supervised in the sauna. It is best to start a child at a lower temperature and/or have them sit on the lower bench where it is cooler.
If you have any health concerns, then it is best to check with a physician before you use a sauna. Most importantly, use your common sense and self awareness, your body will let you know when it is time to exit the sauna when it gets to hot. Remember to drink plenty of water before and after the sauna to keep yourself hydrated.
