It was a beautiful day in May when Lindsay Kujawa took her almost 2-year-old son, Ronin, to a party.

But what was supposed to be a fun-filled day quickly turned to horror when Ronin fell into a hot tub while his mother, who was sitting inches away, turned briefly to speak with a friend.Kujawa, who lives in Murrieta, California, and writes a blog "Delighted Momma," flew into action instantly, scooping the child out of the water within seconds.He appeared visibly upset, but OK, as he coughed up some water, Kujawa recalled. But hours later, Ronin's health took a turn for the worse.At first he started having a weird cough. Then Ronin spiked a fever and became lethargic. Then his blood oxygen levels dropped to distress levels.Kujawa wrote that emergency room doctors determined that Ronin was experiencing a condition most parents haven't heard about secondary drowning.Dr. Andy Miller, medical director at the Children's ER at Lehigh Valley Hospital's Cedar Crest campus, said secondary drowning can happen after a child inhales a small amount of fluid."One tablespoon of water in the lungs is all it takes to cause problems," he said, adding that as a result of the fluid getting into the lungs, it can sometimes cause a reaction that could cause edema of the lungs, blood oxygen levels to drop, chemical pneumonitis or the inflammation of the lungs due to harsh chemicals, and in some cases, death.Miller said that this type of drowning doesn't necessarily occur only with swimming. It could happen in anything that contains water, such as a bathtub, bucket or even a puddle.Miller did caution that secondary drowning is not always going to happen if a child inhales water."It's still not common," he said, noting that a small percentage of children who experience near-drowning incidents will actually have a real problem from inhaling water after the incident. "Regardless, we may not be seeing it every day, but it's something we should know about."Symptoms to look for after a near-drowning experience include trouble breathing, coughing, chest pain, agitation, lethargy, change in behavior, exhaustion and just acting strange. These symptoms may occur within minutes or hours after the person inhaled the water.Miller advises a parent who notices any changes in a child after swimming, to take precautions and get the child checked immediately."Anytime after a child is swimming and they vomit or have an involuntary defecation, it means something may have happened that you didn't see, and they should be seen," he said. "If you are concerned, bring the child to the emergency room for an evaluation. It's better to be safe than put your child to bed thinking they will be OK and later they are in distress."I can't say enough about water safety," Miller said. "Parents have to watch their children closely and teach them how to blow out water. Parents should also learn CPR and get formal swimming lessons for their children."Ronin spent nearly two days in the hospital after being diagnosed with chemical pneumonitis from secondary drowning before his lungs officially cleared and he was able to go home.