Did he watch the Bad Bunny halftime show?

Store away all the summer clothes if it’s a problem. This is a post-April vacation battle, not a February battle.

I do not understand why you would even buy your son a tank top?

Who cares. He might learn the hard way once, and it's not like he's going to die of exposure in that one occurrence. We don't live in Siberia.

Op, you are overthinking it. Let him wear a tank top.

Natural consequences. Let him look up the weather and feel outside. Offer your recommendation. Then he can choose what to wear. If he’s miserable for a day, he’ll make a better choice tomorrow.

You don’t get to decide when your kid is cold. This isn’t a hill I am willing to die on. Let him see the natural consequences of this action. Pack a long sleeve shirt, layer him up, and off to school you go!

I would just say no. My kid has beloved clothes she sometimes wants to wear in the winter and I just say no, it's not appropriate for the weather.

One time she threw a huge fit about wanting to wear this dress that she'd outgrown and was too short for her, and when I suggested wearing pants with it she threw another fit about wanting to wear tights. Her grandmother was visiting and she wanted to wear this outfit for a special outing with her grandmother. It was just a couple hours so I finally said, "you know what, okay. I am telling you right now that if you wear this, you will be extremely uncomfortable the entire time. But if you won't listen to me and insist, you can wear it."

And she was absolutely freezing (she of course also wore a warm coat and boots and hat and mittens but it didn't matter because her legs were just not sufficiently layered). She came home early from the outing and since then she fights me a lot less on wearing weather-appropriate clothes.

But that was just a couple hours and grandma was on board for letting her learn that lesson. I wouldn't do that with school where it's the whole day and I'm off loading her misery onto teachers and admin.

I mean, what? Lots of kids wear tank tops as undershirts.
My kid wears shorts sleeves, shorts and a sweatshirt to school until it's like 15 degrees outside and he's fine.

Throw them away.

DS, 8, got some tank tops over the summer. No sleeves was perfectly fine in the DC heat but now… He says he would wear a hoodie and jacket over it but if he lost an outer layer I worry he would freeze. How do I handle this?