ISO 11079 provides a method of calculating thermal resistance or insulation required from the temperature difference across the clothing (difference between the mean skin temperature and the mean temperature of clothing) divided by the metabolic rate minus any heat loss by breathing and evaporation (which is balanced by any heat transfer by convection and radiation to the environment). Hand protection is usually traded with task requirements and manual dexterity, and the selection of glove and mitten configurations is part of clothing system design. For thermal comfort, survival and the avoidance of cold injuries, it is essential to pay particular attention to the protection of the hands from cold. Whether the clothing involves smart clothing or not, it is essential to integrate any garments with the clothing system and identify its objectives. An important point about smart and active clothing is that local effects may influence the effectiveness of thermoregulation and stimulate heat loss.