A word to the wise: stay out of the emergency room this long weekend.

The reason has nothing to do with the so-called July phenomenon—when a new crop of doctors in training arrive at your local hospital—and everything to do with alcohol, firecrackers, fistfights and reckless drivers.

July is the first month of the academic medical year, and marks the arrival of a new crop of medical residents and second-year med students taking their first crack at patients on the hospital floor. 

Although some have feared that the arrival of newbie docs would correspond with clumsy misdiagnoses and an increase in patient mortality, study after study has shown the July phenomenon is total bunk. “It’s good hypothesis that hasn’t really been born out by the empirical data,” says Gary Rosenthal, an internist at the University of Iowa in Iowa City and the Iowa City VA Medical Center, who has studied the question.

But July Fourth, like any holiday weekend, is still fraught with danger, says Shahriar Zehtabchi who works in one of the busiest emergency rooms in the country: Kings County Hospital in New York. “During summer holidays we get a lot of trauma patients,” he says, “Whether this is violence-related or car accidents or just kids falling off their bikes.”

“The already overcrowded emergency rooms are going to be extra-overcrowded not only because of the number of trauma cases but because a lot of clinics and private offices are closed,” he says.

Even patients who experience a possible heart attack, and are admitted for cardiac tests or angioplasty will end up waiting because many doctors will be on vacation. “It’s going to be long, long waits,” Zehtabchi says, and delays in care put “patients in danger.”

Image of hand courtesy pmarkham via Flickr