As much as 25% of your body heat is lost through your head. The Polar Hoodie is designed to trap that heat and keep your head and torso warm in frigid waters down to 6°C/43°F. The Polar Hoodie is constructed with a 2.0mm neoprene hood and 2.5mm neoprene body-vest that is lined with ThermaFur for incredible comfort and warmth.