I have had summer dresses made fromm hankerchef weight summer wool...

I believe it. Once I had to represent the Clan at an August Gathering ... I had only a heavy weight wool kilt ... strangely, although temp was in 80s, I was not overcome ... evidently what keeps out the cold will also keep out the heat.
Aren't the black cloak things worn by Arab Nomads also a heavy wool? And aren't they worn day and night?
Helen?