A blood blister forms when skin and small blood vessels are damaged without breaking the skin. Trapped beneath the skin surface is some blood and skin fluid. Blood blisters are commonly caused by accidents in which the skin is pinched by a tool or a heavy weight, or they may occur from constant rubbing back and forth.
1 Sunshine hours in Chicago, Illinois range between 3:42 per day in December & 10:14 for each day in July. 2  The longest day of the year is 15:02 long and the shortest day is 8:57 long.  The longest day is 6:04 longer than the shortest day.
It's official: Winter is here. The 2014 winter solstice was Sunday, Dec. 21, at 5:03 p.m. CST. It marks the shortest day of the year and the longest night. The upshot is that after Sunday, the days will begin to get longer again by several seconds each day.