One of the most common comments we get on social media is: “Can cold-plunging cause a heart attack?”

It’s a fair question. When people see videos of others stepping into ice baths or water below 5°C, it’s normal to assume it might be dangerous.

The reality is that cold plunging is a safe and beneficial practice when done in a controlled way. That said, it’s also true that not everyone should do it. There are certain health conditions where cold-plunging may pose risks—and in this article, we’ll explain which ones.

What Is Cold-Plunging?

Cold-plunging is a wellness practice that involves immersing the entire body in cold water for a short period of time—usually 2 to 5 minutes.

Any temperature below 13°C is considered cold exposure and is enough to unlock its benefits. Going colder than that depends on each person’s level of adaptation and their intention to train mental resilience. The same applies to time: around 2 minutes already delivers most of the benefits of cold exposure.

Why take a cold-plunge? Some of its main benefits include:

• Anti-inflammatory effects

• Faster recovery and muscle pain relief

• Improved circulation and cardiovascular strength

• Reduced systemic inflammation

• Better mental health and mood

What Does Cold-Plunging Do to the Body?

When you immerse yourself in cold water, the body triggers a series of physiological responses:

• Initial shock: The fight-or-flight response is activated. Blood vessels constrict, heart rate increases, and breathing becomes faster.

• Hormone release: Endorphins, dopamine, and norepinephrine are released, improving mood and reducing stress.

• Cold adaptation: After about 30–40 seconds, breathing becomes more controlled and heart rate begins to slow as the vagus nerve is activated.

• Brown fat activation: Fat and glucose are burned to generate heat.

• Vasodilation: After exiting the water, blood returns to the extremities, carrying oxygen and nutrients.

Who Should Not Cold-Plunge?

Although cold-plunging is safe for most people, there are certain groups for whom it’s not recommended.

Cardiovascular conditions

Cold-plunging is primarily not recommended for people with:

• Arrhythmias

• High blood pressure

• Heart disease

Cold exposure places stress on the heart due to vasoconstriction and sudden changes in heart rate. While this stress can be beneficial and help strengthen the heart in healthy individuals, it can be too intense and potentially dangerous for people with existing heart conditions.

In these cases, cold-plunging should be avoided—or at the very least, done only after consulting a physician or cardiologist.

Respiratory conditions

Those with asthma or other respiratory issues should also consult a medical professional. The cold shock can cause rapid, shallow breathing, which may worsen these conditions.

People who are sick or fighting an infection

If you’re dealing with the flu, a cold, fever, or any kind of infection, it’s best to avoid cold-plunges. Your body is already under stress fighting illness, and extreme cold only adds to that load. Wait until you’ve fully recovered.

Epilepsy

Cold exposure is a strong stressor and may trigger complications. Anyone with epilepsy or neurological disorders should consult their doctor before attempting cryotherapy.

Pregnant women

Cold-plunging is not recommended during the first trimester of pregnancy, which is the most delicate stage. The vasoconstriction caused by cold exposure could reduce blood flow to the uterus and pose a risk to the baby.

From the second trimester onward, cold-plunges may offer benefits such as reduced swelling or improved sleep—but only with medical approval and under safe conditions.

If your doctor has given you the green light, keep the following in mind:

• Avoid very low temperatures; 13–14°C is more than enough

• Keep sessions short—no more than 2 minutes

• Listen to your body and exit the water if you feel uncomfortable, excessively cold, or start shaking

• Always be accompanied by someone who can help you in and out and monitor you

Tips for Cold-Plunging Safely

These are our four golden rules:

• Don’t overdo it—neither with time, temperature, nor frequency

• Listen to your body at all times

• Focus on your breathing

• Cold-plunging should be a helpful, pleasant tool—not something that makes you suffer or harms you

If you’re a beginner, the best approach is to start gradually—ending your showers with a few seconds of cold water. Over time, you can slowly increase your exposure.

Once cold showers no longer feel overwhelmingly uncomfortable, you can move on to ice baths. Start slow, both in temperature and duration. Begin at 13°C with 1-minute sessions, and avoid doing it every day—it’s not necessary.

Recommended Step-by-Step for Cold-Plunging

This is the cold-plunge approach we usually recommend at Alfa Humans:

1. Relaxation and mindset. Take 3 deep, controlled breaths. Calm your mind and nervous system. Enter the water relaxed.

2. Hands first. Submerge only your hands for 1 minute. The hands are often the most uncomfortable due to the high number of nerve endings. This helps prepare your body.

3. Committed immersion. Enter smoothly. Inhale as you submerge your feet and exhale as you lower your entire body. Keep moving—if you stop halfway, it becomes much harder.

4. Breath focus. Use deep breaths to regulate heart rate and calm the mind. Inhale through the nose, exhale through the mouth.

5. Rewarming. After exiting, do light movement for twice the amount of time you were in the water—squats, horse stance, etc.

Conclusion

Cold-plunging can be a powerful tool for improving physical and mental health. However, it’s not suitable for everyone.

• If you have a medical condition, always consult your doctor before starting.

• If you’re healthy and curious, start slow and listen to your body.

If you want to learn more about cold exposure and it's benefits, keep exploring our Wellness Journal.