Should I say something??

So, my daughter is in preschool. The school requires me to walk my daughter to the door during drop off and pick her up at the door when it's time to go home. (Which is totally fine, i wouldn't want my 3 year old running from my car to get to her class)

Everyday during drop off & pick up I notice that another mother with 4 children walk from their house to the school. Her oldest is probably 4 (who is in the same class as my daughter) and her youngest couldn't be older than 6 months.

I live in Utah. It's super cold and there's snow outside. This mother and her 3 older kids are in coats and hats. However, she does not have her tiny little baby in anything but a long sleeve tshirt, pants and socks (usually)

This baby is obviously so cold everytime I see him, his face is always so red and his nose is runny. I'm always wearing a jacket and I'm freezing cold i can't imagine what this baby feels.

Should I say something to the mother and maybe ask her to at least put a blanket over her child so he doesn't freeze. Would that be over stepping. I usually stay out of this kind of stuff, I think parents should raise their kids however they want but.... I feel so bad for this baby.

What's even more messed up is that the baby grabbed his mom's finger and she said in a playful baby voice "oh, you're hand is so cold" and then she put her hand in her pocket. I almost said something then and there.

What should I do!?!?!

Should I say something, or just leave it??