Good article.
Here in the Charleston area, it is the humidity that's the killer, you just can't cool off because there is no breeze and it's a virtual sauna outside most of the time.
We exercise the dogs in the morning or evening. And don't over do.
I'm always telling my students to cool their dogs when we train agility as well.
A lot of this is common sense, unfortunately a lot of people don't have much of that.
Thanks for posting this as a warning/reminder.