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.
Cards: Standard deck of 52 cards. How to play: In a two-player game, each player is dealt seven cards. In a game with three or four players, each player is dealt five cards. The rest of the deck goes facedown in a pile, with the top card turned up beside it. This is the discard pile. The player to the left of the dealer discards a card from his hand that matches either the number or suit of the top card in the discard pile. For example, if the card is a five of hearts, he could play any heart or any five.