At many office workplaces women can wear open toed shoes. Now, if a man did, he more than likely wouldn't still be working there. It's like with men having to always wear long pants there.
In society, women's issues mean a lot, but men's issues don't mean much or anything. And, invariably if a woman brings up women's issues she gets praised and liked, if a man brings up men's issues he gets contempt. So, that's why men can't wear those there.
The one asking the question doesn't say where, and what heat, temperature. Here where I am it is cold and rainy now.