It happened during a school trip to Hanoi in Vietnam. Tim, who wants to be known only by his first name, was with his classmates from an international school in Singapore. They gathered for a party in his hotel room and started playing drinking games.

Before he knew it, the then 14-year-old Singaporean had downed a full bottle of Black Label whisky, neat, in a space of two hours. "Everyone was just trying to drink as much as he could," he said.

He started feeling weak all over and could not stop vomiting. He also felt very cold and his heart began racing. "At first, I thought it was just food poisoning. Then I realised my vomit was green," he recalled.

Because he and his friends were drinking on the sly, they did not dare tell their teachers about his condition. He endured another three days of constant vomiting before his friends took him to a doctor. He was prescribed medication that finally made him feel better.

The bout with binge drinking made Tim vow never to do it again. Now 26 and working in Shanghai in the fashion industry, he still remembers the excruciating pain and discomfort of the experience vividly.

Tim is one of the lucky ones. In March last year, a Chinese national in Singapore, Ms Zhu Shaoyun, paid for her drinking binge with her life. She had downed a jug of beer and knocked back a bottle of Cordonbleu brandy - neat - in half an hour. She died from alcohol poisoning.

This is a result of consuming large amounts of alcohol in a short period of time.

If a body's blood alcohol content (BAC) exceeds 300mg/100ml, it has reached a point where a person crosses over from harmless intoxication to alcohol poisoning, said Dr Chan Keen Loong, senior consultant psychiatrist at Alexandra Hospital, who deals with patients admitted for alcohol overdose.

Associate Professor Suresh Pillai of the National University Hospital's (NUH) emergency department said that downing more than eight drinks in a row would cause BAC levels to exceed 500mg/100ml, which is fatal.

At such levels, the alcohol affects the brain's control over the person's consciousness, heartbeat and breathing. It also impairs the gag reflex, increasing the risk of victims choking on their own vomit and suffocating.

Constant vomiting will lead to dehydration, which causes irregular heartbeat, kidney failure and decreased blood supply to the brain, leading to a coma.

Breathing will also become irregular and the person's blood pressure will fall dangerously low, depriving the brain of oxygen, which can cause coma or severe brain damage.

Patients suffering from alcohol poisoning need to be taken to a hospital quickly where they will be monitored and put on intravenous fluids for re-hydration.

Oxygen therapy, where pure oxygen is pumped into the lungs through a machine, is carried out to increase the supply of oxygen to the body. Any obstruction in his airways will also be cleared to ensure normal breathing, said Dr Chan.

Even if a person survives alcohol poisoning, he could suffer irreversible brain damage and memory loss.

It is not always easy to tell if a person has reached a dangerous level of intoxication. Drunk people often display the same symptoms such as unconsciousness, slurred speech and vomiting.

But Dr Chan said there are some signs that should set alarm bells off - mental confusion, inability to wake from unconsciousness, constant vomiting, seizures, fits, slow or irregular breathing, low body temperature and bluish skin colour or paleness.

Women also need to be more careful as they suffer more effects from alcohol than men and generally at a faster rate too.

According to the Australian Department of Health and Ageing, teenagers, who have a smaller body mass, are also more vulnerable to the effects of alcohol because they have not built up a tolerance for alcohol.

They are also less able to judge their own levels of intoxication.

WHAT TO WATCH OUT FOR
Critical signs of alcohol poisoning include:
1. Mental confusion
2. Inability to wake from unconsciousness
3. Vomiting (constantly or while passed out)
4. Seizures, fits
5. Slow or irregular breathing (less than eight breaths a minute)
6. Hypothermia (low body temperature)
7. Bluish skin colour or paleness
8. Call 995 for an ambulance in such cases.

TOP 10 DEADLY DRINKS
The alcohol content of strong drinks:
1. Moonshine: 96 per cent
2. Everclear: 75.5 to 95 per cent
3. Rum: 40 to 95 per cent
4. Whisky (above): 40 to 92 per cent
5. Absinthe: 53 to 74 per cent
6. Tequila: 45 to 50.5 per cent
7. Vodka: 40 to 50 per cent
8. Gin: 40 to 48.5 per cent
9. Ouzo: 40 to 46 per cent
10. Aquavit spirit: 35 to 45 per cent

Sources: The Guardian, University of Prince Edward Island School of Nursing, Canada

This article was first published in Mind Your Body, The Straits Times, on January 8, 2009.