Cold plunges and cold-water immersion have gained popularity for their reported ability to reduce muscle soreness, lower stress, improve sleep quality, and support recovery after exercise. Research shows that cold exposure triggers physiological responses such as vasoconstriction and stress hormone release that can influence inflammation, circulation, and mood in the short term, but long-term health benefits remain inconsistent and limited by current evidence. While time-dependent effects on stress, sleep, and quality of life have been observed in systematic reviews, claims about enhanced immunity, mood regulation, or systemic inflammation reduction are not firmly supported, and cold plunges carry significant safety risks that require caution, especially for at-risk individuals.