Protective clothing protects wearers from hostile environments, including extremes of heat and cold. Whilst some types of protective clothing may be designed primarily for non-thermal hazards (e.g. biological hazards), a key challenge in all protective clothing remains wearer comfort and the management of thermal stress (i.e. excessive heat or cold). This book reviews key types of protective clothing, technologies for heating and cooling and, finally, modeling aspects of thermal stress and strain.