When you take the plunge, the chilled water instantly numbs the nerves that surround your joints and muscles, causing the release of hormones and endorphins. The release of hormones and endorphins acts as an analgesic, which relieves inflammation and alleviates muscle and joint pain. Much like an icy-hot, the cold also interferes with your brain’s perception of pain and dulls pain nerve transmissions, providing your body with pain relief (12).