Cold plunges: Healthy or harmful for your heart?

The purported health benefits of cold plunges include less stress, better sleep, and enhanced immunity, but the evidence is thin. While the practice may ease muscle soreness after intense exercise, it may have detrimental effects on gains in muscle power and strength. Because the shock of cold water on the skin can raise heart rate and blood pressure, people with cardiovascular disease (especially heart rhythm abnormalities) should avoid the practice.