When Heat Isn’t Safe: Who Should Avoid Saunas, Steam Rooms and Hot Tubs?

Hot tubs, saunas, infrared saunas and steam rooms have been used for relaxation and wellbeing for centuries. For most healthy adults they are safe and enjoyable when used sensibly, and many people find that regular heat therapy becomes one of the most relaxing parts of their weekly routine.

However, heat exposure does place temporary demands on the body. Blood vessels widen, heart rate rises, and the body loses fluid through sweating. These responses are completely normal, but they also mean that certain health conditions require a little extra care.

In many cases this does not mean heat therapy needs to be avoided entirely. It simply means speaking with a GP first and approaching heat sessions more cautiously. Understanding when to seek advice helps ensure that hot tubs, saunas and steam rooms remain safe and enjoyable parts of a healthy lifestyle.

How heat therapy affects the body

Although hot tubs, saunas and steam rooms feel very different, the body responds to them in broadly similar ways.

When exposed to heat:

• Blood vessels dilate to release heat
• Heart rate rises
• Sweating increases fluid loss
• Core body temperature rises

The way heat is delivered varies between environments.

Hot tubs warm the body through hot water immersion. Traditional saunas heat the surrounding air. Infrared saunas warm the body more directly using infrared radiation. Steam rooms combine heat with very high humidity.

Despite these differences, each environment raises body temperature and affects circulation. For most healthy adults these changes are temporary and well tolerated, but for certain medical conditions it is sensible to check with a GP before regular use.

If you would like a clearer understanding of how warm water affects the body, our article on how hydrotherapy works in hot tubs explains the basics in more detail.

Cardiovascular conditions

Heat therapy affects the circulatory system. As blood vessels widen, blood pressure can fall slightly and the heart works harder to maintain circulation.

For people with certain cardiovascular conditions, these changes may require careful management.

It is usually wise to seek medical advice before using saunas, steam rooms or hot tubs if you have:

• Heart disease
• A recent heart attack
• Unstable blood pressure
• Heart rhythm disorders
• A history of fainting linked to blood pressure changes

Some people with stable cardiovascular conditions may still be able to use heat therapy, but it is sensible to check with a GP or specialist first.

Pregnancy

During pregnancy, maintaining a safe core body temperature becomes particularly important.

Health authorities including the NHS advise caution with high heat environments such as hot tubs, saunas and steam rooms during pregnancy, as these can raise core body temperature and increase the risk of overheating, dehydration or fainting.

For this reason, many pregnant individuals choose to avoid them altogether, particularly during early pregnancy. Anyone who is pregnant and considering heat therapy should speak with their healthcare provider for personalised guidance.

Reduced sensation, including peripheral neuropathy

Some medical conditions affect the body’s ability to sense temperature accurately.

Peripheral neuropathy, a form of nerve damage commonly associated with conditions such as diabetes, can reduce the ability to feel heat or pain properly. The NHS describes peripheral neuropathy as damage affecting the peripheral nervous system, often in the hands and feet, which can reduce normal sensation.

When this happens, it becomes harder to judge when temperatures are becoming too high. This can increase risk in hot environments such as hot tubs, saunas or steam rooms, because someone may not realise that their body is overheating or that surfaces or water temperatures are too hot.

Other neurological conditions or injuries can also affect temperature sensitivity. If sensation is reduced, it is sensible to seek medical advice before regularly using heat therapy.

Diabetes complications

Having diabetes does not automatically mean someone cannot use a sauna or hot tub.

However, organisations such as Diabetes UK note that complications like nerve damage or circulation problems can affect temperature sensitivity. If these complications are present, it is sensible to speak with a GP before regularly using hot tubs, saunas or steam rooms.

Medications that affect temperature regulation

Some medicines can affect how the body manages heat or fluid balance.

For example, certain medications may influence blood pressure, sweating, hydration or alertness in warm environments. Examples can include diuretics, some blood pressure medicines, sedatives, and some antidepressant or antipsychotic medicines.

If you take regular medication and are unsure whether heat exposure is appropriate, a GP or pharmacist can provide helpful guidance.

Alcohol and heat exposure

Alcohol and high heat environments are not a good combination.

Whether in a hot tub, sauna or steam room, alcohol can increase dehydration, affect judgement and make it harder to recognise when you are becoming unwell.

For safety, it is best to avoid alcohol before or during heat therapy sessions.

Safe heat therapy guidelines for everyone

Even for healthy individuals, sensible habits help ensure heat therapy remains safe and enjoyable.

General guidance includes:

• Hot tubs are typically set between 37C and 40C
• Saunas operate at much higher temperatures
• Steam rooms combine heat with very high humidity
• Short sessions are usually best, especially if you are new to heat therapy
• Stay hydrated before and after sessions
• Take cooling breaks between heat exposures
• Leave immediately if you feel dizzy, lightheaded or uncomfortable

If you are new to hot tubs, our guide to how long you should stay in a hot tub covers session length and temperature guidance in more detail.

Using heat therapy responsibly

For most people, hot tubs, saunas, infrared saunas and steam rooms can be a safe and rewarding way to relax, recover and unwind.

Understanding your personal health circumstances simply helps ensure that heat therapy is used responsibly. When in doubt, speaking with a GP provides reassurance and clarity.

At Hot Tubs Oxfordshire, we believe wellbeing should always be approached in a balanced and informed way. When used sensibly, heat therapy can be one of the most enjoyable ways to slow down, recharge and make time for your own wellbeing.

References

NHS. Health things you should know in pregnancy.

NHS. Peripheral neuropathy.

Diabetes UK. Diabetic neuropathy.