Dear unpleasant young woman I passed today:
Your heeled boots are very cute. They are also extremely impractical and insensible when we're in the middle of a freeze-thaw cycle. Wearing such footwear is certainly your prerogative and I don't mean to criticize; heaven knows I've made some questionable footwear choices myself.
I was only trying to be helpful when I warned you about the unexpected slippery patch of sidewalk that I had just barely survived. While some patches of ice are obvious, sometimes there is an extremely slick layer of ice hidden at the bottom of puddles of deceptive depth. This was the case today and I felt that it would be kind to warn you. I nearly wiped out there in my sensible footwear several seconds before, and I wasn't walking in heels while texting like you were.
Being rudely dismissive to me for warning you about such a thing seems quite unnecessary. Now I kind of hope you fall in a puddle in such a way that you aren't seriously hurt but so you have to go through your afternoon looking like you wet yourself in your expensive designer jeans.
All the best,