The title made me laugh, so of course I had to read the article: The Boys Who Wear Shorts All Winter. We all know this boy, right? (And, yes, it's always a boy, according to the article.)
The author makes some good points about this phenomenon. It could be that some children are sensitive to different fabrics and textures and shorts are simply more comfortable. Maybe this is just a way for some children to exert some independence. Or maybe they do just "run hot."
Regardless of the reason, the author's point is that we don't need to overreact when our children don't want to wear what we think of as weather-inappropriate clothes. Unless it's -15 degrees, we really don't need to worry about children getting frostbite the minute they walk outside. (Please note the negative sign in that sentence.) As parents, we need to pick our battles and for many families, this one probably isn't a battle worth waging. Furthermore, if we decide to battle our children on this front, they're unlikely to back down, especially if they're tweens or teens. The last thing a child that age wants to do is prove their parent right. So, probably, they'll put on warmer clothes when they get cold, but only if it's their choice to do so.
A good way to promote independence in preschoolers and teach them what's appropriate to wear and what's not is to provide them with two acceptable choices. For example, "You may wear the blue knit cap or the baseball hat. Which do you choose?" Or, "You may wear long pants or tights and a skirt. Which do you choose?" Always make sure both choices are acceptable to you!
And if it's just one of those days and you cannot, just cannot, get your child to cooperate and change into something appropriate and your only choice is to send them to school in their PJs or not come to school at all, please, send them in their PJs. We don't mind at all.