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Author Topic: Temperature/Heat Index  (Read 3765 times)

Offline Carolyn

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Temperature/Heat Index
« on: 14/08/2007 19:51:03 »
What is a heat index.  I understand that it's the temperature it feels like, but not the actual temp.  The last two weeks have been unbearably hot here. I keep hearing it's 95 with a heat index of 103, or it's 103 with a heat index of 110.  We've had several days recently where the heat index was 110.  If it feels like 110, why isn't that what the temp is?
« Last Edit: 14/08/2007 22:00:19 by Carolyn »


 

Offline neilep

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« Reply #1 on: 14/08/2007 19:54:37 »
Isn't it the first few pages of a Radiator Catalogue ?
 

Offline Karen W.

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« Reply #2 on: 14/08/2007 21:49:55 »

Pulled this from wiki! There were some more interesting things there also!

http://en.wikipedia.org/wiki/Heat_index

Heat index
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The Heat index (HI) is an index that combines air temperature and relative humidity to determine an apparent temperature how hot it actually feels. The human body normally cools itself by perspiration, or sweating, in which the water in the sweat evaporates and carries heat away from the body. However, when the relative humidity is high, the evaporation rate of water is reduced. This means heat is removed from the body at a lower rate, causing it to retain more heat than it would in dry air. Measurements have been taken based on subjective descriptions of how hot subjects feel for a given temperature and humidity, allowing an index to be made which corresponds a temperature and humidity combination to a higher temperature in dry air.

In Canada, the similar humidex is used in place of the heat index.

At high temperatures, the level of relative humidity needed to make the Heat Index higher than the actual temperature is lower than at cooler temperatures. For example, at 80 F (approximately 27 C), the heat index will agree with the actual temperature if the relative humidity is 45%, but at 110 F (roughly 43 C), any relative-humidity reading above 17% will make the Heat Index higher than 110 F. Humidity is deemed not to raise the apparent temperature at all if the actual temperature is below approximately 68 F (20 C) essentially the same temperature colder than which wind chill is thought to commence. It should be noted that humidex and heat indexes are based on temperature measurements taken in the shade and not the sun, so extra care must be taken while in the sun.

Sometimes the heat index and the wind chill factor are denoted collectively by the single terms "apparent temperature" or "relative outdoor temperature".
 

another_someone

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Temperature/Heat Index
« Reply #3 on: 15/08/2007 13:36:14 »
Thanks, Karen - I guessed it was something like that, but had not got around to looking it up to confirm my suspicion.
 

Offline Carolyn

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« Reply #4 on: 16/08/2007 03:02:30 »
Thank you Karen.
 

Offline JimBob

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« Reply #5 on: 18/08/2007 04:51:43 »
Karen,

You really do not understand what a heat index is and there should be a disambiguation page for heat index at Wiki P.

The heat index is also a male phenomena. It is the heat a male feels upon visual stimulation by the female form. It is, as is the "10" index, subjective to the male's preferences, age, (I am getting older, unfortunately and it is just appreciation now) and societal norms and mores - and more.

There are also other heat indices common to females only and some common to both and also some only found in ewes or ewes and swine.

 

Offline Carolyn

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« Reply #6 on: 18/08/2007 04:59:29 »
LOL...Thanks for that detailed definition of heat indexes.
 

Offline neilep

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« Reply #7 on: 18/08/2007 05:06:00 »
LOL...Thanks for that detailed definition of heat indexes.

Mine was the best !!
 

Offline Carolyn

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« Reply #8 on: 18/08/2007 05:35:17 »
Of course it was!   ;D ;)
 

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« Reply #8 on: 18/08/2007 05:35:17 »

 

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