Is this some kind of rule?

This suit is made of wool. It's an extremely lightweight wool, blended with some extremely lightweight synthetic, so the cloth of the suit itself would almost be comfortable on moderately hot days. It's light gray, which is not an unreasonable compromise between dignity and temperature. It's obviously meant to be a summer suit. I'm wearing a silk shirt under it, and cotton socks, because it's 85F and likely to get hotter before my job interview.

What idiot decided to line my pants with acetate? This must be the worst possible material for hot weather. It feels hot when it's hot, and clammy when it's cold. (It's not great for winter, either, but the pants of my winter suit are more likely to touch thermal underwear than skin.) Are they trying to comply with some rule that all formal clothing has to be uncomfortable, even if there's no structural reason for it?