Humidity

Well I'm not contradicting you, just saying simple gas laws suggest you're unlikely to be right, or at least that it is a very small effect compared with inefficiency of sweating. Just in a spirit of scientific enquiry!

But…then you said ”The moisture in the air holds the heat”, which is something quite different!

alternatively, as the air warms up it is capable of holding more water vapour without it actually starting to rain.

Hence evaporation slows down (try drying a towel outside in Fiji - almost impossible) and you feel more discomfort.

Don't really see the difference myself.

At 30C and 88% humidity, the water has twice the specific enthalpy contribution that the much larger mass of nitrogen around it has.

'The moisture in the air holds the heat' could mean something to do with the Specific Heat Capacity of humid air, which is only marginally different from the SHC of dry air. ie the amount of energy needed to raise the temperature of 1 kg of air by 1 degree.

Calculator:

This is called the 'sensible heat'.

But what most people are concerned about is the 'latent heat', ie the energy taken up during evaporation of sweat from liquid to gas, and the effects of relative humidity on that process.

'The water vapour holds the heat' seems an inaccurate way of describing that effect.

Theo

Exactly Ive been very comfortable in a pool of water at 36°C . Not so much in air at 36°C and near 100% humidity

I had one of those but it died :-(

In English?

Moist air holds more heat, and it is not a trivial amount; because the latent heat of condensation for water is large.

Thank you very much :-)

QED.

:-)

On the topic of heat, atmospheric gasses, and water vapour, I’m sure that anyone that has been following this thread can now see the inherent flaws in Eunice Newton Foote’s experiments of 1856.

The rest of the article is an interesting exercise in the use or non-use of words to influence a narrative:

But it doesnt affect how hot you feel

You mean it doesn't affect how hot YOU feel, I will decide how hot I feel thank you.

Oh FFS.

-- "Anyone who believes that the laws of physics are mere social conventions is invited to try transgressing those conventions from the windows of my apartment. (I live on the twenty-first floor.) "

Alan Sokal

He has a fair point; there may be a psychological effect of humid air exacerbating the sensation of hotness, additional to the physical effect on cooling efficiency.

Or to put it more simply, a lot of English people just don't like warm weather.

It's simpler than that. This English person doesn't like being told how hot he feels but will decide that for himself.

As usual you have reverse ferreted,. Its not about how hot you feel, its about the physics of cooling.

You didn't say 'high humidity air makes me feel hot' you said 'high humidity air makes me feel hot BECAUSE warm air 'holds more heat''

I never disagreed with the fact that it makes you feel hot, merely the reason why, which is based in objective science. And can therefore be challenged on a factual basis, unlike your feelings, which may be whatever you say they are, or not, depending on how much of a liar you are.

The science says that evaporative cooling which is how humans mostly lose heat, is affected by the humidity of the air you are sweating into, pure and simple.

Not the amount of heat already 'contained' in the air/water vapour.