Before a Sauna Session: A Hydration, Medicines, and Stop-Signs Checklist

By NewLifeWellnessCenter.com Editorial Team. Sources checked October 6, 2026.

If you only have thirty seconds, here is the short version. Before you step into a sauna, make sure you feel well, are not already dehydrated, have not been drinking alcohol, and know whether any medicine you take affects how your body handles heat. Keep the session short (Harvard Health and Brown Health both cap sessions at about 15 to 20 minutes), and decide in advance that you will leave the moment something feels off. The rest of this page turns that into a checklist you can actually use.

This is general education, not medical advice, and it is not clearance to use a sauna. If you have a heart or blood pressure condition, take regular medicines, are pregnant, or are unsure, talk with your doctor or pharmacist first.

Your Pre-Session Checklist

Run through these before you go in. If you cannot check a box, that is a good reason to wait or ask a professional.

• I feel well today. Harvard Health advises against using a sauna when you are ill. Brown Health's physician-authored guidance lists fever and acute infection among the situations to discuss with a physician first.
• I am hydrated. CDC/NIOSH lists not drinking enough fluids as a risk factor for heat-related illness. Harvard Health suggests two to four glasses of cool water after each sauna session, and the American Heart Association's heat guidance recommends a few cups of water before, during, and after going outside or exercising in the heat.
• I have not had alcohol, and I will not have any right after. Harvard Health says to avoid alcohol before and after a sauna, and Brown Health says not to use alcohol before or immediately after.
• I have checked my medicines. Some medicines change thirst, sweating, or blood pressure. See the next section.
• I know my own risk factors. CDC/NIOSH lists older age, pregnancy, a previous heat-related illness, certain medications, and some health problems as factors that raise the risk of heat illness.
• I have set a time limit. Harvard Health says to stay in no more than 15 to 20 minutes. Brown Health says to limit time to no more than 20 minutes and not to exceed 212 degrees Fahrenheit.
• I have a plan to cool down gradually. Harvard Health recommends cooling down gradually. Brown Health cautions that people with heart disease should avoid jumping into ice water or cold pools afterward because it can destabilize heart rhythm or blood pressure.

Medicines: What to Ask Before You Heat Up

This is the step people skip most often. The CDC's clinical guidance on heat and medications describes several types of medicine that can affect how the body copes with heat. The guidance is written for clinicians and for hot weather in general, not for saunas specifically, but the body's challenge is similar: staying cool, hydrated, and steady. Per the CDC, examples include:

• Diuretics, ACE inhibitors, and ARBs (often prescribed for blood pressure or heart conditions): linked to reduced thirst, fluid loss, and a higher risk of fainting.
• Beta blockers: linked to decreased sweating.
• Antipsychotics and tricyclic antidepressants: linked to impaired or decreased sweating and temperature regulation.
• Anticholinergic antihistamines: linked to impaired temperature regulation.
• Stimulants such as methylphenidate and amphetamines: linked to a higher body temperature.

The American Heart Association adds that heart medicines including beta blockers, ACE inhibitors, calcium channel blockers, and diuretics can intensify the body's response to heat.

That list is not complete, and your own situation matters more than any list. A pharmacist can often answer a quick question like “Does anything I take affect how I handle heat?” in a couple of minutes. One firm rule from the CDC guidance: avoid abruptly stopping any medication without a plan. If a medicine worries you, talk to the person who prescribed it instead of skipping doses on your own.

Alcohol and Heat Do Not Mix Well

Three of the sources reviewed for this page say the same thing in different words: skip alcohol before a sauna, and skip it right afterward too. The American Heart Association's heat guidance, written for outdoor heat and exercise, also lists caffeinated drinks among those to avoid during heat exposure. If you want something to sip, plain cool water is the simple choice.

The Stop-Now Symptom Card

Save this section or screenshot it. Knowing your exit signs ahead of time makes it much easier to act on them in the moment. Harvard Health puts the general rule plainly: if you feel unwell during your sauna, head for the door.

Leave the heat and start cooling down if you notice:

• Headache
• Nausea
• Dizziness or light-headedness
• Weakness
• Heavy sweating
• Muscle cramps or spasms

These match the heat exhaustion and heat cramp symptoms listed by CDC/NIOSH. Their first-aid guidance for heat exhaustion is to get out of the heat, take cool liquids, and apply cold compresses to the head and neck, and to seek medical care. For fainting or near-fainting, CDC/NIOSH says to sit or lie down in a cool place and drink slowly.

Call 911 right away if you or someone with you has:

• Confusion or altered thinking
• Slurred speech
• Loss of consciousness
• Hot, red, dry skin with a very high body temperature (the American Heart Association describes heat stroke as 103 degrees Fahrenheit or higher)

CDC/NIOSH identifies heat stroke as an emergency requiring a 911 call. Do not wait to see whether it passes. Muscle pain together with unusually dark, tea-colored or cola-colored urine is another sign CDC/NIOSH says needs immediate medical care.

Who Should Ask a Professional First

Brown Health's guidance says people with any of the following should discuss sauna use with their physician before going in: unstable angina, a heart attack within the past two weeks, uncontrolled high blood pressure, decompensated heart failure, severe aortic stenosis, low blood pressure, dehydration, fever, acute infection or inflammation, or skin breakdown. Harvard Health specifically advises people with uncontrolled high blood pressure or heart disease to check with their doctors. CDC/NIOSH adds pregnancy, older age, and a previous heat-related illness to its list of risk factors for heat illness.

If any of that sounds like you, bring this checklist to your appointment. It gives you a concrete place to start the conversation.

Limits of This Checklist

It helps to be clear about what this page cannot do. The CDC/NIOSH and CDC clinical pages cited here are about heat stress and heat illness in general and do not mention saunas, so we have applied their symptom and risk-factor information to sauna sessions as a practical safety lens. The Harvard Health article was last updated in May 2020, and the Brown Health article is a physician's guidance aimed mainly at people with heart conditions. The 212 degree Fahrenheit figure comes from a single source and may not suit every sauna, so check the manufacturer's instructions for the specific sauna you use. Nothing here predicts how your body will respond, and no checklist replaces advice from someone who knows your health history.

What to Do Next

1. Read through the checklist above before your next session and see whether every box is a clear yes.
2. If you take any regular medicine, ask your pharmacist or prescriber whether it affects heat tolerance, thirst, sweating, or blood pressure.
3. If you have a heart or blood pressure condition, are pregnant, or have had heat illness before, ask your doctor before you begin.
4. Pick your time limit and your exit signs before you walk in, not once you are already warm.

If you want to keep reading about sauna topics on this site, you can browse the Far Infrared Saunas section. Articles there are general educational reading and are not a substitute for the guidance of your own clinician.

Sources

All sources below were opened and checked on October 6, 2026.

• CDC/NIOSH, Heat Stress: About (last reviewed March 3, 2026). Used for the list of heat-illness risk factors, including dehydration, certain medications, older age, pregnancy, and previous heat illness.
• CDC/NIOSH, Heat-Related Illnesses (last reviewed March 3, 2026). Used for symptoms and first aid for heat exhaustion, heat cramps, heat syncope, heat stroke, and rhabdomyolysis.
• CDC, Heat and Medications: Guidance for Clinicians (last reviewed September 18, 2025). Used for medicine classes that can affect heat tolerance and the advice not to stop medications abruptly without a plan.
• Harvard Health, Sauna Health Benefits: Are saunas healthy or harmful? (last updated May 14, 2020). Used for the 15 to 20 minute limit, alcohol, water after the session, cooling down gradually, and leaving if you feel unwell.
• Brown University Health, Saunas and Your Heart: Is It Safe to Use a Sauna If You Have Heart Disease? (June 13, 2023, by Wen-Chih “Hank” Wu, MD). Used for conditions to discuss with a physician, the 20 minute and 212 degree Fahrenheit limits, alcohol, and avoiding ice-water immersion with heart disease.
• American Heart Association Newsroom, When the heat rises, so do heart risks (June 20, 2025). Used for hydration, avoiding alcoholic and caffeinated drinks in heat, heart medicines that can intensify heat response, and heat exhaustion and heat stroke warning signs.

This article is for general educational purposes only and is not medical advice. It does not diagnose, treat, or prevent any condition. Talk with a qualified healthcare professional about your own situation before using a sauna.