Air circulates under a kilt, so I don't find that the kilt itself makes your legs hot. Where a kilt gets hot is under the belt, but that really isn't any different between a light weight kilt and a heavy weight kilt.

What I find is a real killer is the hose. Even the all-cotton piper hose that we wear with our band uniforms in the summer are _hot_ (especially when it's 90 degrees and 99% humidity and we're marching down the road in a parade). Much more so than the kilt.

One difference between 16 oz Strome and, say, 11-12 oz Dalgliesh tartan that is worth keeping in mind is the "scratchiness" of the wool. The 16 oz tartan is scratchier, and, when your skin is warm or sweaty, it can be more irritating.