Dry heat vs humid heat with same heat index (average, place, wind speed)

[lvoc]

Originally Posted by justanokie

The heat index is a scale for how relative the heat feels for a given temp and humidity. So they should feel the same.

Probably more based on what you are accustomed to growing up as to which you would prefer.

For me, growing up with both, I prefer the hot/dry combo because I hate walking around in sweaty clothes and its easier to get out of the heat by stepping into a shade and when it turns night it gets much cooler.





Actually you sweat more in humid weather than dry weather because the sweat is less effective in cooling you therefore you will sweat more to get the same amount of cooling.

You sure? Where does the question postulate equal cooling? In fact the rate of heat transfer through sweating is higher in the dry case...by a lot at equilibrium.

[EricS39]

The heat index is correlated to how much sweat production is needed to cool you

Example
Miami temperature 89 degrees
Miami possible Heat index 105 degrees

Phoenix temperature 107 degrees
Phoenix possible Heat index 99

Death Valley 121 degrees
Death Valley possible heat index 105 degrees

In this case we are not comparing Miami to Phoenix ... Miami you would sweat more and Phoenix would be more comfortable

We are comparing Miami to Death Valley
Miami I say wins because the sweat production in this scenario would equal Death Valley so you would FEEL same discomfort level

But at least the Miami un-working sweat that's not doing a good job cooling you down, would be on your skin to evaporate later when you get inside

The Death Valley sweat would be evaporated and not there

The Miami situation also can be made better with a paper fan

The Death Valley situation would be no hope except for water spray


Also heat index degrees does not account for wind speed. Higher wind breeze will reduce humid heat discomfort but not dry heat discomfort as much. Air quality and natural plant sugar produce will also reduce humid heat discomfort more effectively than dry heat discomfort. Rubbing alcohol will also relieve humid heat discomfort but not dry heat discomfort.

Dry heat discomfort is based on where the temperature is so extremely high that despite the lack of humidity, it is now so extremely hot that it's uncomfortable level to be out.

[43north87west]

Dry heat. No contest here. It's much easier to stay cool in dry heat, and it's more comfortable.

[EricS39]

Yes, it's easier to stay cool in dry heat because the heat index is lower without the humidity (unless you raise the dry temperature by a lot), but read the subject of the thread carefully.

[j96g]

Walk into a sauna and that's a humid feel.

Turn on a fan heater and close the door in a room in summer and that's dry.

Both uncomfortable, but you couldn't help but sweat in humid and feel burned up in dry heat. But I find you can make yourself "feel" cooler faster in dry heat. I've lived in Deep South Texas and now in Colorado, so I kind of get both, but yet to feel a real hot dry heat like Phoenix. The worst I felt in Texas was a temp of 105 with a heat index of 128.

[justanokie]

Originally Posted by EricS39

Again, if the heat index is the same in both scenarios, then the question being asked is not the one you think it is.

Yes, i actually do understand the question.

Originally Posted by EricS39

You think they are asking if you would rather carry lots of feathers or lots of heavy bowling balls

That's not what this question is. This question is rather, "would you rather have to carry 100 pounds worth of bowling balls, or 100 pounds worth of feathers."

so your saying that the question isn't whether I want to carry lots of feather or lots of bowling balls but rather whether I would want to carry lots of feathers or lots of bowling balls.

Originally Posted by lvoc

You sure? Where does the question postulate equal cooling? In fact the rate of heat transfer through sweating is higher in the dry case...by a lot at equilibrium.

Its implied by setting the heat index the same for the two scenarios. When you have a given temp, your sweat production required to cool your body will increase as the humidity increases. Therefore you sweat more in high humidity verse a low humidity case.

In this specific example where the heat index is set equal you should theoretically sweat the same and experience the same discomfort. At that juncture its purely a matter of preference since there is no scientific way to conclude which one is most comfortable since they are by definition equally comfortable.

So its probably going to depend entirely on which environment you are more accustomed to. For me, growing up in both, I prefer to have the higher temp and remain dry, rather than walking around in wet clothes. Also the heat is easier to escape with shade and the AC works better in doors. Also you get bigger temp drops in the dry climate at night making them and the mornings much cooler.

[Rangerdude_Charlie]

I prefer a dry climate of the Mountain West. I can handle hot dry heat it is hot and humid that is really bothering me especially living in the South for the first time in my life.

[divisionbyzero0]

my friend was in mecca for umrah 2 years ago at summer. It was about 40-45 C and dry, and he said it wasn't that hot. On the other hand here 33C and humid feels so hot, even the similar heat index 40-42 C.

[divisionbyzero0]

Dry heat is dangerous. Dry 40C can feels "cooler" than humid 33C. And 40C is very dangerous. Dry heat is "silent but dangerous" heat.

[lvoc]

Originally Posted by divisionbyzero0

Dry heat is dangerous. Dry 40C can feels "cooler" than humid 33C. And 40C is very dangerous. Dry heat is "silent but dangerous" heat.

"Dangerous"? We open our cooling centers at 105 I believe and work outside goes on well past that level. It does become important to have water but it is hardly dangerous.