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.
Sunlight in August at Chicago lasts for 13 hours and 48 minutes a day on average. The longest day of the month is the 1st with 14 hours and 24 minutes of daylight. By the end of the month, the days have shortened to 13:10 from sunrise to sunset.