The Funny Pic Thread, Pt. 8

[Jerchap2]

 

[rhino]

Why, Yes there is.

If you believe the heat indexers, you will think that it actually feels like it is hotter. When in actuality if it were 109 with no humidity it would actually be more comfortable than your 95 with high humidity.

You need to take into account temperature and humidity and prepare accordingly. Just like you need to take into account temperature and wind chill and prepare accordingly.

Like I said You cannot Convince people.

You seem to be trying to make a point that doesn't really make sense (to me).

The idea behind reporting "humiture" or heat index is that it approximates the effect of the humidity on how well your body can cool itself via perspiration. It's an approximation and will vary from person, but it's a pretty good approximation for most people. The point is to give people an idea of how well their body is going to be able to cool itself and it seems to work well.

I too have been in high temps with fairly low relative humidity (114 in Walnut Creek, California in the summer of 1989). I assure you that it was not more comfortable than 95-100 F with 95% relative humidity, which I have also felt.

 

[jamil]

You seem to be trying to make a point that doesn't really make sense (to me).

The idea behind reporting "humiture" or heat index is that it approximates the effect of the humidity on how well your body can cool itself via perspiration. It's an approximation and will vary from person, but it's a pretty good approximation for most people. The point is to give people an idea of how well their body is going to be able to cool itself and it seems to work well.

I too have been in high temps with fairly low relative humidity (114 in Walnut Creek, California in the summer of 1989). I assure you that it was not more comfortable than 95-100 F with 95% relative humidity, which I have also felt.

Thank you.

(You must spread some Reputation around before giving it to rhino again.)

Some people perspire more than others. The evaporate cooling effect can be felt by some more than others. I remember my dad telling me about when he was stationed in the deserts of the M.E. during WWII. He used wet cloths a lot to help keep cool. Perspiration alone wasn't enough to make it bearable.

 

[rkwhyte2]

 

[Jerchap2]

 

[Dr.Midnight]

 

[Jerchap2]

Ah, the good old days.

 

[JettaKnight]

I’ve been in 109 degree temps before. It’s still ****ing hot.

"Don't worry Mr. Pinette, it's a dry heat - you're gonna make it!"

[video=youtube;5GnFGxOWgt8]http://www.youtube.com/watch?v=5GnFGxOWgt8[/video]

 

[ArcadiaGP]

 

[Spear Dane]

"Don't worry Mr. Pinette, it's a dry heat - you're gonna make it!"

[video=youtube;5GnFGxOWgt8]http://www.youtube.com/watch?v=5GnFGxOWgt8[/video]

Actually... not so much.

 

[dudley0]

.... and after he lost so much weight. Started being healthy.

That is like I always say... all healthy people die.

He was a great comedian tho. Wish I could find his part about when he went to Hawaii. That was funny.

 

[BugI02]

Thank you.

(You must spread some Reputation around before giving it to rhino again.)

Some people perspire more than others. The evaporate cooling effect can be felt by some more than others. I remember my dad telling me about when he was stationed in the deserts of the M.E. during WWII. He used wet cloths a lot to help keep cool. Perspiration alone wasn't enough to make it bearable.

Dude, the right end of that chart, in the purple (how apropos). Contact with temps of 175 - 180F is hot enough to cause 2nd degree burns. Do you really think thats what it feels like, or do they perhaps extend that chart into fantasyland for some other reason

 

[Jerchap2]

 

[rhino]

Dude, the right end of that chart, in the purple (how apropos). Contact with temps of 175 - 180F is hot enough to cause 2nd degree burns. Do you really think thats what it feels like, or do they perhaps extend that chart into fantasyland for some other reason

Maybe . . . but a few of things . . .

When it's really hot and sunny, the air temperature inside of a car can reach 170 deg F. Some industrial environments can reach similar temperatures (actaeon can tell us more). The chart is about air temperatures, not the temperature of a surface.

Thinks about what it's like to get into a car when it's really hot inside. The air doesn't burn you, but when your hands touch something it can be painful.

Burns are created by heat transfer, not absolute temperature. Heat transfer is related to temperature (primarily temperature differences), but is also affected by the mode(s) of heat transfer (conduction, convection, radiation) and the parameters that affect the rate of each mode. Back in the 1980s or 90s, a woman tried a long distance swim in the Atlantic, but she had to quit when she got hypothermic. When her support team pulled her from the water, the temperature difference between their hands and her skin was enough produce a sufficient heat transfer rate to cause minor burns in the shapes of their hands and fingers.

For exposure to the air, we're talking about convection heat transfer. For air and skin, that's going to be slower than the rate of conduction heat transfer between skin and a chunk of metal or even a vinyl car seat using the same difference in temperatures. A person can survive very hot air temperatures briefly, but not so much laying on a giant cast iron griddle at the same temperature.

In addition, increasing relative humidity increases the film coefficient, which is what determines the convective heat transfer rate for a given temp difference. Humid air will heat (or cool) a body faster than dry air.

And of course I am discussing this in the absence of the evaporative cooling that is affected by temperature difference (skin to air), relative humidity, and a host of physiological and physical factors.

 

[actaeon277]

Yes, I've troubleshoot a remote control crane in the top of the building. We had to check the temperature, to see if the electronics could handle it.
It was 179 degrees.
I did not get burned, by the air or the metal.
I did however, question my choice of employment rather emphatically (or is it.. vigorously?).

And I was wearing 3 layers of clothes.

 

[Thor]

On the ramp at Nellis in August...just sayin...210F. That August was the longest year of my life; it got below 100F once for an hour.

 

[Jerchap2]

 

[Wolfhound]

 

[Wolfhound]

 

[BugI02]

Maybe . . . but a few of things . . .

When it's really hot and sunny, the air temperature inside of a car can reach 170 deg F. Some industrial environments can reach similar temperatures (actaeon can tell us more). The chart is about air temperatures, not the temperature of a surface.

Thinks about what it's like to get into a car when it's really hot inside. The air doesn't burn you, but when your hands touch something it can be painful.

Burns are created by heat transfer, not absolute temperature. Heat transfer is related to temperature (primarily temperature differences), but is also affected by the mode(s) of heat transfer (conduction, convection, radiation) and the parameters that affect the rate of each mode. Back in the 1980s or 90s, a woman tried a long distance swim in the Atlantic, but she had to quit when she got hypothermic. When her support team pulled her from the water, the temperature difference between their hands and her skin was enough produce a sufficient heat transfer rate to cause minor burns in the shapes of their hands and fingers.

For exposure to the air, we're talking about convection heat transfer. For air and skin, that's going to be slower than the rate of conduction heat transfer between skin and a chunk of metal or even a vinyl car seat using the same difference in temperatures. A person can survive very hot air temperatures briefly, but not so much laying on a giant cast iron griddle at the same temperature.

In addition, increasing relative humidity increases the film coefficient, which is what determines the convective heat transfer rate for a given temp difference. Humid air will heat (or cool) a body faster than dry air.

And of course I am discussing this in the absence of the evaporative cooling that is affected by temperature difference (skin to air), relative humidity, and a host of physiological and physical factors.

Granted, but I still argue that the chart is subjective - temperature x at humidity y feels like temperature x'. My skepticism arises from the likely dearth of (surviving) people that know what an OAT of 180F feels like well enough to relate it to temp x at humidity y

I suspect they postulated a relationship that "worked" for a narrow range of conditions and then pushed the parameters ay beyond any range where they should have had confidence in the results. Not an uncommon problem