Believe it or not but this soggy strategy can help ease a fever and clear congestion by drawing blood to the feet which dramatically increases blood circulation.
Best method: Warm your feet in hot water. Then soak a thin pair of cotton socks in cold water then wring them out and slip them on just before going to bed. Put a pair of dry wool socks over the wet ones. The wet socks should be warm and dry in the morning, and you should feel markedly better.