Bath water temperature is part of wellness routines that take you to both ends of the temperature scale, from sweating it out in a sauna to shivering in an ice-cold bath. But how does your heart respond to these extremes, especially when you move straight from one to the other?
Dr Dhirendra Singhania, director of interventional cardiology at Yashoda Medicity, weighed in to comment on how cold plunges and saunas affect your cardiovascular system, who should be cautious, and which warning signs need closer attention.
“For the heart, these extreme water temperatures are not passive,” he alerted. “Sudden changes in temperature make blood vessels and the cardiovascular system respond quickly.” This means your heart and blood vessels have to adjust to the temperature change. How safe is this physiological change for your wellbeing?
What happens during a cold plunge?
Many wellness routines include taking a cold plunge in ice-filled water. But this causes the blood vessels to adjust. How? Dr Singhania said, “Cold water leads to constriction of blood vessels. This can lead to increased blood pressure and put stress on the heart. In initial moments, breathing may be quickened and hard to control.”
Is it safe? To this query, the cardiologist expressed concern that it is safe only when a person is healthy, and they can actually tolerate short and controlled exposure. Even for them, though, prolonged immersion or exposure to extreme cold can put stress on the cardiovascular system.
Who should be cautious? The doctor flagged that people with heart disease, uncontrolled blood pressure, or serious heart rhythm problems should be particularly careful. He also advised against holding your breath during a cold plunge, as this can further alter your heart rate and blood pressure.
What happens in a sauna?
Heat affects the body in the opposite way. Dr Singhania described the physiological response: Heat acts in the contrary way. In an effort to dissipate heat from the body, vessels dilate, an increase in the volume of blood flowing through the skin, and an increase in heart rate within the body occur. Additionally, sweating results in further loss of fluids.”
To put it simply, blood vessels widen, and more blood flows towards the skin to release the heat, then the heart beats faster. Sweating also causes fluid loss. If not cautious, then it may lead to dehydration.
Who can use a sauna, and how should they approach it? “In the case of most healthy adults, moderate sauna use can be incorporated into an exercise routine, but it should not be viewed as an alternative to working out, healthy eating, sleeping adequately, or treating diseases (hypertension, etc.). Ensuring proper hydration is essential in the case of longer sauna sessions,” the cardiologist explained.
Is it safe to go directly from a sauna into an ice bath?
Some people take these routines by integrating the two. They move straight from a hot sauna into an ice bath. But this sudden switch between temperature extremes calls for caution, as per the cardiologist.
“Rapid temperature changes from extreme heat to extreme cold can undergo a drastic transition whereby the blood vessels easily expand or constrict suddenly. Sudden changes can cause noticeable alterations in blood pressure and heart rate,” Dr Singhania warned firmly.
The expert advised beginners to start with milder temperatures and breathe normally during cold immersion. Warning signs that mean they should stop include chest pain, dizziness, fainting, difficulty breathing, or persistent palpitations.
Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.
