(Memphis) Parents, if you've never heard of a "bomb," ask your college-age child about it.
It's a shot of liquor dropped into an energy drink.
Alcohol mixed with energy drinks is today's cocktail of choice for young people.
However, healths experts say high quantities of caffeine alone is dangerous.
An energy drink is how Patrick Johnson starts most mornings. "At least one a day, preferably early, because it kind of just gets my day going," says Johnson.
Not a big deal, but, Johnson knows when he's had too much. "I've had times where if I don't eat and I'll have like two or three in a row, like I'll get this feeling of like a hole in my stomach," Johnson adds.
Mild symptoms compared to what could happen. "My heart started beating, it felt really weird, it was going really fast," explains Cody Yearwood, who had several episodes before finally seeing a doctor.
"It scared me," Yearwood admitted. A young athlete, Yearwood was initially in denial.
Doctors said his regiment of energy drinks and workout supplements was too much, on his then 17-year-old body.
"They put me on a heart monitor for a month. I had an irregular heartbeat from the beginning, so all those things came together," Yearwood said, who didn't know about his heart condition, until the over consumption of energy drinks.
"It can cause seizures, and again the higher the dose that goes up, people can pass out, go comatose," explains Dr. John Benitez, the Managing Director of the Tennessee Poison Center where workers take calls about caffeine.
"People can get a caffeine overdose, so that's certainly and potentially a dangerous thing."
The poison center codes calls by type such as, "caffeine only" and "caffeine with alcohol".
A report from the American Association of Poison Control Centers shows calls related to caffeine and energy drinks jumped from just over 700 in 2010, to more than 3,000 in 2011.
Benitez says tracking the data is still relatively new.
"It's not a reported mandate that you have to report these to a poison center, so our numbers can get skewed just by how many people call us in a given year," explains Benitez.
Dr. Casey Laizure, a professor in the Department of Clinical Pharmacy at the UT Health Science Center, says under-reporting and a lack of research are part of the problem.
"We've basically conducted an experiment by allowing energy drinks to be marketed in the United States at these high levels of caffeine without knowing what the consequences were," says Laizure.
Some energy drinks have around 100 milligrams of caffeine, that's similar to an eight ounce cup of coffee, others can be as high as 500, and in some cases the caffeine content isn't clear.
Laizure says what we do know is that caffeine, even by itself, consumed in high quantities, over a short period of time is bad for the body.
"With a cup of coffee, you sit around and drink coffee over 20 to 30 minutes, with an energy drink, if you really want to get it for its caffeine effect, you can consume it in a minute or two, and that's going to create a big difference in how the caffeine is in your body and your brain," Laizure says.
Laizure applied for a grant to do his own study. Participants will down an energy drink within five minutes, and researchers will check caffeine concentrations in their blood.
"When we do this kind of study, we actually can then model it and determine, well, what will happen if you drink five energy drinks within 10 minutes?"
Until the answer is clear, Dr. Laizure offers a word of advice. "These high levels of caffeine may not be appropriate for young children and pre-teens to be consuming."
Yearwood says he hasn't had an energy drink in years, but takes responsibility for what happened. He and Johnson encourage other young people to do the same.
"You can over do anything and I definitely over did it," says Yearwood.
"You have to know what you're doing, just like with anything, you have to be responsible," Johnson says.
The American Beverage Associated didn't comment specifically on our investigation, but refuted recent reports from the government and the American Academy of Pediatrics about the dangers of energy drinks.