(CNN) - So many of us will take to pools and oceans to cool off this summer and while the risk of drowning in the water is a known hazard, there is another risk called "secondary drowning" that you may not know about
Lifeguards often call it "parking lot drowning" because it can happen hours after a swimmer leaves the water. CNN reports that you can think of this as near drowning. A swimmer in the pool might accidentally inhale water or have a close-to-drowning incident. But then they brush it off and appear to be fine immediately after.
But experts warn not everyone is in the clear at this point. The water left in a swimmer's lungs could cause swelling. The lungs then have a harder time exchanging oxygen and it causes the heart to slow. The symptoms to look out for in your swimmers: persistent coughing, shortness of breath, chest pain, fever and mood changes -- and could appear anywhere from one to 24 hours after the initial incident.
If caught early doctors can remove the fluid from the lungs but if not treated, the experts say this can quickly turn into a more serious condition, like cardiac arrest and it can be fatal. Many people don't know about this but it is an important thing to learn about and to watch out for, especially in all those little swimmers out there this summer.