How cold is “too cold?”

I’m not a fan of winter - I think the thing I like least is the cold weather’s effect on my health (triggers my asthma). Snow is nice, and I like winter clothes. But the cold is where I draw the line. A few weeks ago, I considered 30°F too cold (I live in southern Ohio). However, after recently experiencing 9° with a wind chill of -10° I think 30° is warm (relatively).
What’s your breaking point with cold weather?