[Paddlewise] windchill

>>Windchill is the calculated effect the wind has on wet skin, not on
clothed, dry suited skin.  Although the wind does have an effect on the
amount of heat removed from your body through teh insulation layers and the
dry or wet   suit.
>>The effect is similar, but not the same.  It is like measuring apples   and
>>oranges.
>>
>>John LeBlanc

>You are technically correct, but then what do you call the thermal effect
 of wind on a wet drysuit? At eight degrees F. with a strong wind blowing,
 the surface of a wet drysuit would be much colder in the air than in the
water -- at least, until the
>
>Chuck Holst
>

Chuck, I don't mean to be nitpicking on details, but it's probably helpful
if we have a full discussion of windchill.  If I understand them accurately
I think technically your statement is correct and so is John LeBlanc's.
  At air temperature of 8 deg. F the surface temperature of an wet drysuit,
exposed to the air, will be very close to 8 deg. F, whether the wind speed
is 10 or 25 mph.  However the RATE of heat loss will be much higher in the
25-mph wind. In any case the surface temp won't go below the air temp. The
phenomenon of heat being whisked away faster and faster as the wind speed
goes up is termed windchill.
  And that, as we all know, increases the hazard of hypothermia, whether
it's over exposed skin or over protected and insulated skin.  Our
exothermic (heat-generating) bodies can produce heat only up to a limited
rate.  If the rate of heat loss exceeds the heat generation rate then body
temperature begins to drop, first in the extremities, feet, hands, then
legs, arms, then progressively in the brain and body core.
	Insulation protects us by reducing the rate of heat loss, but does not
eliminate that heat loss.  On the other hand, fire, sunshine, hot showers,
hot air and hot drinks have the effect of actually adding heat to our bodies.
	I suppose we could capitalize Windchill when it refers to the effect of
wind over skin and use lower case windchill for other cases, over drysuits
etc., the underlying physics is the same in principle.

	Now most of us also know that we can protect ourselves from windchill by
standing out of the wind.  But it has been observed even more effective to
stand downwind from some Paddlewisers.  While hypERthermia is unlikely, one
should be a bit careful here, as the situation may become unpleasant,
depending on which end of the Paddlewiser's body the hot air is coming
from.  :~)
	Cheers,
	John Somers

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