Does heat and sweat also cause eczema?

It won't cause eczema per se but it can aggravate an existing eczema condition. I had eczema as a child but it's mild now as an adult. It does get aggravated every now and then in Singapore's humid and hot weather, especially in my neck area.

yes it is possible. for my son heat and sweat makes him get all red and he starts itching.