It's 2 a.m. and the bars are closing. In the middle of the crowd exiting the bar, John is losing his balance and grabbing onto people to hold him up. He stumbles to the ground. Laughter surrounds him as he struggles to gain composure. He attempts to lift his head, but is overcome and passes out. As John regains consciousness, he gradually becomes aware that he is in a hospital emergency department.

Sound familiar? Alcohol poisoning occurs at Penn State, just as it does on university campuses around the country. In cases such as John's, heavy drinking can result in a variety of medical emergencies, and in a worse case scenario, in death. To understand how alcohol poisoning happens, we need to know how the body responds to alcohol.

Alcohol is classified as a depressant, which can cause dramatic changes in the body and brain. Alcohol slows down many body functions, including blood pressure, heart rate and breathing. When you consume a large amount of alcohol into your system, the "slowing down" can lead to "passing out" and unconsciousness. The vital organs, heart and lungs, can be slowed to the point of stopping.

Have you ever witnessed a person drink himself or herself unconscious? What should you do if you encounter someone who could be suffering from acute alcohol poisoning? It is dangerous to assume a person will be fine "just sleeping it off." First, try to find out if the person is responsive. Are they unconscious? Are they having trouble breathing? Can they be awakened? Call their name. Try pinching their skin. Remember alcohol is a depressant and it will numb the nerves, so by pinching the skin you can gauge how far along in the "overdose" process they are. Turn the person on their side so that if they get sick and vomit, the airways will not be blocked and they will not choke. Stay with them. Monitor their breathing. Make sure they do not roll over on their back. Call 911.

Even though you may be worried about getting into trouble with the police, this is a situation where you'll need to put your concerns second because it is more important to save a life.

Alcohol also "creeps up" on women. Here's Lisa's story. Lisa's friends are planning on "helping" her celebrate her twenty-first birthday.

It's late in the evening and Lisa is on her third shot, followed by a beer chaser. During her first hour of drinking Lisa drank two glasses of Long Island Ice Tea (for the uninitiated it includes at least four different types of alcohol). Two hours later and Lisa is mixing drinks and having a great time. Suddenly, she feels dizzy; she's emotional, crying and laughing at the same time.

She takes another shot, for a total of four shots, two Long Island Iced Teas and several glasses of beer--all in less than four hours.

Her friends see Lisa is unresponsive and notice her breathing is irregular with few breaths and then what seems like no breaths. They wisely call 911 and she is taken to the emergency room.

How much alcohol will cause poisoning? Different people experience different effects. Some people who have little tolerance for alcohol or whose body is sensitive to the drug could be seriously at risk after six or seven drinks. Another person may have ten drinks, be very intoxicated, but not end up unconscious.

How much is too much? There is no way to know what amount is safe because people respond differently to alcohol.

Many things affect how alcohol makes a person act and feel.

For example, size, age and gender affect how you will respond to alcohol.

In addition, how a person drinks and how much food is in the stomach affects how the body responds to alcohol. Females, smaller people or people who drink on an empty stomach usually react to alcohol more quickly than muscular males who eat shortly before they drink.

Using alcohol with another drug can increase the effects of both drugs. Many deaths have resulted from mixing alcohol with illegal drugs such as marijuana, cocaine or heroin.

To avoid these side effects, eat a full meal before "partying," try to stick to one drink per hour at most, and drink non-alcoholic beverages in between every alcoholic beverage.