Yes, having a child with actual sensory issues takes it to a whole new level. Its actual distress for them to wear certain things.
And that's what I'm seeing. This morning we had a big issue because her skirt that she has deemed wearable, was in the laundry. She was clearly distressed and fighting to hold it together while I laid out her options for her: shorts, pants, shorts and leg warmers. She ABSOLUTELY refused every option and appeared significantly distressed. After firmly establishing which things were OK and which things were not, I told her I was going to check on her after taking a shower to see what she had chosen. After my shower, she had selected a long sleeve shirt and a pair of shorts. It's so bizarre how she was so anti-shorts for SOOO long and now she can't stand pants. She has issues with shirts too, but today was OK. Also issues with socks, but we just don't make her wear those so that solves that problem... except for the smell it causes.
Oh, and the temperature dropped today. Winter is clearly on its way now. So, we'll see how she handles that. To be clear though, we live in a moderate climate and dressing in shorts is more of a comfort issue than a safety issue. It isn't literally freezing or anything.
I guess I'm wondering what you are classing as distress? Are you sure it's not just prolonged repeated tantrums? My son will come across as early distressed sometimes when he gets upset, absolute hysteria ensues but I've always just been firm on expectations and over time he's come round.