Extreme weather clothing

Application of Modeling and Simulation in Protective and Extreme Weather Clothing... 

Because of the overlap with models describing heat and mass transfer in fabrics and clothing, only a few examples relating to extreme weather clothing will be examined. 

Extreme weather clothing is usually made up of a number of layers with a still air layer on their surfaces and possibly mobile air layers on top of those. Detailed models take into account dry and wet heat transfer. Dry heat transfer tales place by conduction, convection and radiation, the latter two being most important. Wet heat transfer results fix)m sweating. Water moisture on the surface of the skin evaporates remove large amoimts of heat from the body. The water vapor molecules are transported to the environment in various ways including diffusion, convection, absorption (adsorption), desorption and condensation. Often, finite element modeling is used for the simulations in which the clothing and air layers are divided into a matrix of elements and heat and mass transport. 

The discomfort experienced by humans because of the cold and windy conditions that characterize the summer weather in the Transantarctic Mountains and on the polar plateau is aggravated by the extremely low humidity of the air. Humans working out-of-doors under these conditions must protect themselves by wearing appropriate cold-weather clothing. Their ability to cope with the stressful environmental conditions improves when they are physically fit, well rested, well nourished, healthy, and when they are highly motivated to accomplish their mission (Gunderson 1974). 

Figure 12.1. Factors for consideration in modeling of chemical, fire and extreme weather protective clothing.

Heat prostration—Avoid going outside on hot, sunny days use fans to cool the body if the day is extremely warm sponge the skin with cool water if other cooling measures are not available and wear loose-fitting clothes in warm weather. 

Photosensitivity It is advisable to rest a patient s skin until effects of keratolytic agents subside before beginning tretinoin. Minimize exposure to sunlight and sunlamps, and advise patients with sunburn not to use tretinoin until fully recovered because of heightened susceptibility to sunlight as a result of tretinoin use. Patients who undergo considerable sun exposure due to occupation and those with inherent sun sensitivity should exercise particular caution. Use sunscreen products and wear protective clothing over treated areas. Weather extremes, such as wind and cold, also may irritate treated areas. 

At the other extreme, agricultural pesticide use in the northern United States in the early spring may take place in temperatures at or barely above freezing. Pesticide handlers working in cold weather are amenable to the use of protective suits or coveralls over another set of clothing. In these conditions, however, some rubber or plastic garments may become stiff and brittle. 

Whole body Temperature extremes, adverse weather, chemical or metal splashes, spray or jets from pressure leaks or spray guns, impact or penetration, contaminated dust, excessive wear or entanglement of own clothing Conventional or disposable overalls, boiler suits, specialized protective clothing, chemical protective clothing, chain-mail or acid-proof aprons, high-visibility clothing... 

Regardless of the warming PPC used, people who must work in extremely cold weather should move into warm locations on work breaks, carry extra clothing if there s a chance they ll get wet and most important, learn to recognize the symptoms of cold-related stresses. 

The deployment of soldiers to areas with extreme climates has put new demands on the functions of military clothing for weather protection and comfort. Nowadays, military clothing plays a key role in protecting soldiers and it must perform several functions in the most rugged conditions, and has to be adapted to different fields of operation. At the same time, it is highly desirable that the clothing remain durable and above all, comfortable. 

Waterproof fabric, which is laminated or coated with micro-porous or hydrophilic films, is frequently used in the design of functional clothing for the weather of low temperature, wind, rain, and even more extreme situations. With waterproof fabric, the elothing can effectively protect the body from the wind and water as well as reduce the heat loss from the body to the environment. These functions of waterproof fabric, scientifically, are achieved by signifieantly affecting the processes of heat and moisture transfer through the textile products. 

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