Understanding windchill

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Authors
  1. Osczevski, R.
Corporate Authors
Defence and Civil Inst of Environmental Medicine, Downsview ONT (CAN)
Abstract
The success of the original windchill index is explained in the light of recent work on heart transfer from humans in cold and wind. The question of whether windchill is the effect of wind on exposed skin or on whole body heat loss is examined. A test of the usefulness of windchill indices is described and applied to three proposed indices an equivalent temperature calculated from a revised version of the DCIEM facial cooling model, Steadman's Apparent Temperature, which is based on whole body cooling, and Wyon's manikin-based windchill equivalent temperatures, which were calculated from measurements with average winter cloting. Only the DCIEM facial cooling model equivalent temperatures come close to passing this test. Analysis of data from an Antarctic expedition suggests that people do not dress for the weather, which largely invalidates a basic assumption of AT. Also, simple theoretical considerations suggest that a valid and useful index cannot be derived from a model that considers the heat transfer through normal winter clothing. It is recommended that any new index of windchill be based on the recent model of facial cooling in wind, or on the original windchill index with modifications to the way wind speed is determined.
Keywords
Facial cooling;Face cooling;Thermal instrumented manikins;Human phsiology;Thermal boundary layer
Report Number
DCIEM-SL-2000-025 — Paper
Date of publication
01 Mar 2000
Number of Pages
14
DSTKIM No
CA010615
CANDIS No
515427
Format(s):
Hardcopy;Document Image stored on Optical Disk

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