Updated in June 2015 by the Manitoba Association of Home Economists
Here are four suggestions from the Manitoba Association of Home Economists to keep family members warm while working outdoors in winter:
Wear several different garments over one another so layers of air spaces are built up. Wearer comfort, including freedom of movement, is best with layers of garments. Layers need to fit over each other easily in order to maintain the insulative air layer. Tight fitting layers squeeze the air layers thus reducing the insulating value.
The insulating value of a fabric, known as “thermal resistance” is the ability of a fabric to prevent the flow of heat from one surface though to the opposite side. The most important feature in determining the insulating value is the proportion of still air it incorporates. Air is a poorer conductor of heat than textile fibre and so, is a preferred insulator. However, fabrics insulate because they are comprised mainly of air. For example, a blanket is about 10% fibre and 90% air. Fibres are important because of their ability to trap air and hold it at rest.
Keep the body core (torso and head) warm so that it can send excess heat to the extremities. Extra protection on the body core can add a lot of warming power. This may be particularly important in jobs where hands and feet are critical to performance.
Protect insulation from wind and water by using:
- water repellent rather than waterproof fabrics
- microporous film fabrics such as. Goretex
Provide proper ventilation in clothing so that body moisture vapour can pass off into the environment and sweating can be avoided. This can be achieved with a “spacer” between the body and first layer of clothing. Fishnet or ladder net underwear made of polypropylene can create a spacer. Body heat can pass out of the garment at the neckline. Polypropylene is a good choice since it wicks or draws moisture away from the skin.
