My problem is mostly my hands and feet.
I used to run outside in the winter even when it was 25-30F. Sometimes my hands hurt, but I would wear 2 pairs of gloves, 3 layers of shirts and jackets, a knit had, shorts and pants and that was usually enough.
But cycling is a totally different animal, and I don’t have enough cold weather gear. None of my 10 pairs of running gloves seem to be windproof enough for cycling. One time I was out riding when it was only 50F and my hands went completely numb and were so painful after 10-15 minutes that I could barely grip the bars and had to turn around and come home. Took 10-15 minutes for my hands to warm up. It was SOOO painful and took forever as the circulation came back.
For my first sprint triathlon, the water temperature was 56. My feet went numb. My hand were cold, but okay because the air temp was 60-70. I finally got feeling back in my feet with 1.5km left in the before, shortly before the finish.