The highest form of hardening is: Choose one answer About walking barefoot Oh contrast shower Airless baths winter swimming

The correct answer is: winter swimming.<br /><br />Winter swimming, also known as ice swimming or winter bathing, is considered the highest form of hardening. It involves immersing oneself in cold water, typically during the winter months, to build physical and mental resilience. This practice is believed to strengthen the body and mind, improve circulation, and enhance overall health and well-being.