It is just abysmally cold outside. If you can avoid it, don't walk around outside, don't stand near a window, don't look at anything that's recently been outside. It's crazy.
Sadly, things aren't really going to warm up until next week, when the mid-30's will seem positively balmy.
Here is the forecast from the National Weather Service:
Friday: It will be freezing, obviously, with a high around 24 during the day and an overnight low of about 18 degrees. It will feel colder with the wind chill. There is also a good chance we're going to get some snow once the sun goes down.
Saturday: It will be slightly warmer on Saturday, with a high approaching 30 degrees, but because of the wind you probably won't notice.
Sunday: Clear skies but still really cold. The wind is forecast to be lighter than Friday and Saturday.
Reminder: Nassau County has opened warming shelters for those in need.