The Cofra Thermic boots feature a composite safety toe and a special polyurethane compound that is highly insulating, completely waterproof, and very resistant to harsh chemicals. For these reasons, it has become our best selling boot for those working in the oil and gas industry, or anyone who works outdoors throughout the winter months. Cofra Thermic boots are cold resistant to -50 degrees Celsius (-58 degrees Fahrenheit!). For the best fit and comfort, also buy the optional COFRA Thermic Liner.