Are we better off without pants?

[Tellos Athenaios]

The problem is not whether its cold or warm or neither. It is never actually very cold in the Netherlands: 0-5 °C is a proper "winter" here. During summer temperatures may actually stay at 15-20 °C when it rains rather a lot but they "can" go "up" to 25-30 °C: those are common when it is sunny. 35°C or more is exceptional though.

However it is very humid. Going to Italy in say April you may get temperatures that the Dutch dream of when they think "summer". However the air so much more dry that it feels roughly equivalent to 20 °C in the Netherlands: pleasant, not too sweaty. You can walk for a day in Rome (been there done that) with about 30 °C without feeling too drenched in sweat, whereas a 30 mins bike trip will melt you far worse in the Netherlands when it is that kind of temperatures. I doubt a woolen toga would feel very comfortable compared to the already sticky and uncomfortable sweat-soaked cotton T-shirts.

About winter temps: then the humidity of the climate ensures that what may very well be nearly 5 °C in the shadow feels far, far, far colder than -7 °C in say 200km into Germany.

If you don't understand what I am illustrating: dry air is by all means a very good way to insulate yourself. It is by far the most practical and is in fact the way animal fur "works": trapping bodily heat in a layer of insulating air. It works because air doesn't dissipate heat very much: it doesn't flow very much, it doesn't radiate very much (in any case: your body radiates much, much more) and it certainly conducts very poorly. By comparison water simply soaks up heat (which is why a refreshing bath/shower is the preferred way to cool down on a hot summer's day): it flows a lot, it conducts reasonably well (and has a relatively large J/(kgK) coefficient which means that it must "suck" up a lot of energy per kg before it heats up by one degree). This means that a wet climate as is common in the North does a lot more to suck up heat and if you want to cool down the fact that a lot of water is in the air won't help you much because it interferes with your built-in cooling system: your sweat cannot evaporate very efficiently because the air is already so humid.

However insulation works only well if you "do it properly". Cut out a large hole in your "vacuum flask" and see how good its thermal insulation is now.

EDIT: As for the practical relevance of that: it means that pants/t-shirts and similar are a very "universally useful" piece of clothing. It works here, it works down in South Africa too.