Than PCS 23, maybe. But the old PCS and CS95-MTP trousers are alot thiner than Blues
Also to answer the main question, yes because
UBACS with hero sleeves = breathable = cool = ally = saves lives = Less HIP training
Barrack shirt with hero sleeves = breathable = cool = ally = saves lives = Less HIP training
It depends on which version of blues you’re wearing.
Short sleeved, light blue shirt (that CFAVs can wear) is more breathable and lighter than greens, thus cooler in the warmer weather. The dark blue shirts that cadets have to wear aren’t.
The fact you can wear a wicking t-shirt beneath a barrack shirt etc helps a lot with overall comfort.
It’s not just about whether or not you’re sweating, but how your clothing then deals with the sweat. Acclimatisation doesn’t mean you’re not sweating, it just means your body is now efficient at maintaining the correct temperature.
In this regard, light blue shirts were always a bit better than dark blue (they’d also absorb less heat), but I’m not sure I’d stand by that now that they’re mostly plastic — again, another reason to have our uniform made of natural fibres (or being selective with the purposeful use of man-made fibres).
My latest light blue shirt literally feels like a plastic bag, it’s so hard and unpliable. The dark blue shirts seem much softer and mouldable to the body, especially with rolled sleeves
After carefully reading all of the above, the obvious solution here is clearly (well washed and worn) PCS trousers with a short sleeved No.2 shirt (ideally really old or brand new, not the Chinese-made mostly plastic ones in between).
And a field service cap, because berets are woollen.
I’m in Sussex today. I’d not wanting to be getting into any kind of uniform right now. I’ve stood down before when it’s this hot. And if not, comfortable civvies all the way.
Car said 40C when I got in it earlier! And even after driving only went down to 33C. Not even June yet!