Not enough sleep or disruptions to the sleep-wake cycle (such as those that may occur with shift work or travelling to a different time zone) cause the physiological state known as fatigue. Staying awake for 24 hours leads to a reduced hand-to-eye coordination that is similar to having a blood alcohol content of 0.1.
There are 13 hearts in a standard 52 card deck. There are also 13 diamonds, 13 spades and 13 clubs.
There are 13 spades in a 52-card deck of standard playing cards. Each card in the deck is part of one of four suits: spades, hearts, diamonds or clubs. Spades and clubs are black, while diamonds and hearts are red.