The coolest thing on social media these days may be celebrities and regular folks plunging into frigid water or taking ice baths.
The touted benefits include improved mood, more energy, weight loss and reduced inflammation, but the science supporting some of those claims is lukewarm.
Cold water immersion raises blood pressure and increases stress on the heart. Studies have shown this is safe for healthy people and the effects are only temporary.
But it can be dangerous for people with heart trouble, sometimes leading to life- threatening irregular heartbeats.
Repeated cold-water immersions during winter months have been shown to improve how the body responds to insulin, a hormone that controls blood sugar levels.
Cold water immersion also activates brown fat tissue that helps keep the body warm and helps it control blood sugar and insulin levels.