I think we can all agree that when it’s time to get fancy on a blisteringly hot evening, the ideal choice is a dress that:

1. Is made of a breathable, natural fabric

2. Floats gently away from the body rather than clinging to it

3. Is dark enough to conceal evidence of a “glow” (my late grandmother’s ladylike euphemism for “sweat”).

My pick for this season is Lanvin’s jewel-shoulder cotton midi dress (my preference is black, but it is also available in prune). Not only does it fulfill the previous three requirements, but its hem hits that sweet spot right below the knee: the new length that you’ll be seeing much more of come fall. Bonus: It’s got some bling built right in, so you needn’t fuss with jewelry when you’re feeling all, you know, glowy.

$399 (down from $995!) in black, at 15 E. Oak St., 312-587-1700, or at barneys.com; $495 in prune, at Lanvin, 116 E. Oak St., 312-765-7075