Reginald P. Smithers III wrote:
Calif Bill wrote:
"JimH" wrote in message
oups.com...
On Feb 9, 12:43 am, "Calif Bill" wrote:
"JimH" wrote in message

...





"Calif Bill" wrote in message
link.net...
"JimH" wrote in message
...
"Calif Bill" wrote in message
hlink.net...
"RCE" wrote in message
...
"Calif Bill" wrote in message
link.net...
Wind Chill. I do not think it refers to living tissue. I
think the
definition is how much heat transfer would occur in still air vs.
Moving air. some low speed of air. -15 degrees with a wind
chill
of -30, says the same heat loss would occur if the temp was
-30 and
no wind movement. Nothing to do with evaporation but with the
tendency of the air to heat up near the warmer object, slowing
down
heat transfer.
The term "Wind Chill" applies *only* to living tissue. It
refers to
the rate of cooling (limited by the ambient temperature) that
occurs
to exposed living tissue. The increased rate of cooling can
exceed
the living tissue's ability to replace the heat lost and things
like
frostbite can quickly occur.
The wind can't make it colder. It only makes the rate of heat
transfer and cooling of the object faster. Heat transfer is
higher in
turbulent flow.
Eisboch
Did not realize it applied only to human tissue. Thought it was
just a
rate of heat transfer regards air movement.
Glad to see you finally got it. :-)
actually is the same whether it is tissue or beer cans.
sigh
Sigh my ass. The reason there is a Wind Chill factor is the wind
will carry
away the extra BTU's that still air can not. The body's response
is that
it tries to get to the ambient temperature faster. At the same
speed as if
the air was xx degrees colder. The Wind Chill factor. Same reason
that RCE
stated that turbulent flow will transfer more heat. Laminar flow
will have
a small slow speed component of air right next to the surface. That
small
bit of air will insulate the surface from the air above. Works with
beer
cans also. Same reason that a car radiator works with air flowing
over it.
No fan and hot day and sitting still and you overheat.
Agreed. But the beer or radiator fluid will not go below ambient
temperature no matter how much air you blow on it.

On the other hand, living tissue will and this is traditionally called
the Wind Chill factor.


The flesh will not go below ambient temperature. Wind chill is the
apparent amount of heat that would be lost if the temperature was
lower. If the temperature is 5f and a wind chill is -30f, the flesh
will lose heat at the same rate as if there was no wind and the
temperature was -30. But the flesh will not go below 5f. If it tried
to go below 5f, then the Wind Chill Factor would be the
Wind Heating factor.

Sigh, you do realize he will never understand it.

No, Bill is right. I have attended at least five,
possibly six, cold weather rescue/cold water rescue/
hypothermia clinics presented by Dr. Murray Hamlet
who used to run the Combat Resources Center at the
U.S. Army's Research Institute of Environmental Medicine
(or whatever it is called now), Natick, MA. Dr. Hamlet
is the world's leading expert on cold and cold
weather operations and rescue. Dr. Hamlet says as
part of his cold rescue presentations that "the one thing
you can count on is that a stiff will be a stiff - the
body cannot get any colder than ambient temperature".

I'm quoting directly from my notes taken at the 1999
EMS Cold Weather/Water Rescue seminar presented at the
USCG Academy, New London,CT. The seminar was for folks
involved in paramedic level dive medicine and cold condition
SAR - which happened to include me. :)