A person in distress, flailing above water and screaming for help may be Hollywood's version of a drowning.
But health professionals say that in reality it's the opposite.
"There is no prelude to it at all. They just go down," said Capt. Pat Talkington, training officer for Lawrence-Douglas County Fire & Medical and a certified emergency medical technician. "They're too physically exhausted to do any flailing. I think the thing that surprises people is the quickness that somebody will go under."
While many factors can cause a person to go under water, the stages that follow are typically the same: surprise, involuntary breath-holding, unconsciousness, convulsions caused by lack of oxygen and - if help doesn't arrive in time - death.
When oxygen is cut off from the brain, convulsions occur, which can be dangerous not only for the victim but also for anyone attempting a rescue, Talkington said.
"It's a last attempt in a confused state of trying to get air," he said. "A lot of times you just have to disconnect yourself from the victim in order to save yourself or you could have a possible double drowning."
Dr. Scott Robinson, Lawrence Memorial Hospital emergency department medical director, said that what makes the body's survival tactic unique when drowning is threatened is the dive reflex, where the body lowers its metabolic level to protect the brain. This reflex works more efficiently in cold water than warm water, which Robinson and Talkington said is why more people survive cold-water submersions.
"The colder the water, the more blood gets to the heart, lungs and brain. The body shunts blood to the vital organs," Talkington said.
Knowing personal limits is important, said LMH's Dr. Darin Elo, especially for people who suffer from seizures or other conditions that could be deadly when mixed with water activities.
Stronger swimmers who find themselves in trouble may be able to wave a hand above water or float in a vertical position with their face down, called a dead man's float, said Elo, a certified scuba diver.
This float conserves energy to help a swimmer survive a long period in water. Swimming at a 90-degree angle out of a strong current will also help if a swimmer fears trouble.
"Where you've passed your limits and you panic," Elo said, "it can be very difficult to save your own life."