We don’t know much about the climate Dothraki lived in, much less the weather patterns they had to endure. I assume the Dothraki did though and they choose appropriate garb.
> plains and steppes – that is large expanses of semi-arid grasslands. The very nature of that terrain configuration produces fairly extreme seasonal temperature variations (that is, very hot summers and very cold winters) as well as extreme daily temperature variations (that is, hot days and cold nights) because such places are far from the large bodies of water and also don’t have tree-cover, both of which serve to moderate rapid temperature changes. [...] There’s no reason to suppose the Dothraki Sea would be any different: it sits at about the same latitude as King’s Landing so there is little reason to assume it would be warm all-year-round.
There are more reasons then just weather patterns estimated based on location and terrain for cloth to be less practical tho.
The same blog applies the same pedantry to clothing of other groups and to military aspects of different groups too. It is not like Dothraki were singled out in a blog that otherwise ignores clothing and practicality.
There’s simply no reason to assume Dothraki climate resembles ours.
It is also big on maps and accurate timing of how long it takes to get from place to place. There was even massive complaining when last seasons written by different people failed in that aspect.
There are inaccurate things beyond Dothraki, as described on both this blog and half the internet. But arguing about GoT as if it was Alice in Wonderland crazy fantasy is absurd.
People get badly wounded and yet no one dies of a bacterial infection. There are buildings constructed in ways that our physics wouldn’t support with the assumed materials and tolerances of the assumed period.
There are undead - in fact they are introduced in the prologue of the first book. There is a massive ice wall made by humans in an area that is, as described in the books in permanent winter but yet inhabited by people. And giants. And a few days ride to places that have warm summers. And oh yeah, the seasons last years instead of months and are irregular and unpredictable in length.
But yes, the lands the fictional Dothraki people roamed in should be similar to our grasslands in terms of climate and appropriate garb.
I have read most of the books (a long time ago now) and I believe this happens at least twice. As well as that, there's a lot of talk about cleaning wounds too, even in field situations (typically with boiled wine - apparently similar to Hippocrates).
That's not because of fantasy elements; it's because the author didn't do his research, and instead just went with what he'd seen in countless movies.
[0] https://en.wikipedia.org/wiki/Temperate_grasslands,_savannas...