Keeping your feet protected from cold is essential for overall warmth, your mother told you so didn’t she? Waterproof keeps Mom and your feet happy by offering a boot that is built for extreme conditions. This is a tough 6.5mm semidry boot with an extra-long zipper for easy donning. The heels and toes are strengthened, and the boot has an angled design for less stress while finning. Hypothermia vs Boots. The body reacts to cold and heat by adjusting the blood stream to the external parts of the body, like hands, fingers and feet. Any water temperature lower than the body temp will during the time of the dive affect your core temperature.