When it's hot, like it is now and will be for the next several weeks, Central Florida's lakes and rivers are at their most inviting and dangerous.
"The water's 80 degrees now," said Local 6 Chief Meteorologist Tom Sorrells. "Perfect for water sports and amoebas."
Amoebas kill when they swim up a person's nose and attack the brain. Amoebas have been blamed for 20 deaths in the past five years. The average age of an amoeba victim is just 12-years-old.
Courtney Nash was just 16 when an amoeba invaded her body last summer.
"She gave from her heart. She wasn't afraid to put on Facebook that God was number one in her life, followed by her family and friends," Courtney Nash's mother, P.J. Nash-Ryder said. "Courtney was very giving, great smile, and just a very wonderful person to be around."
But Courtney Nash's giving spirit was taken away last August. The nightmare began on a Thursday after Courtney went swimming with friends in the Saint Johns River.
"Monday night she started to get sick, she started to get a headache, a really bad headache," says Courtney Nash's uncle, Tom Uzel. "Tuesday morning her headache got progressively worse, she started to have a fever of 104, she started throwing up. She threw up about 20 times through the course of the day."
The family rushed Courtney to the hospital where a spinal tap showed parasites got to her brain.
"When they told me it was amoeba, I knew it's usually 99 percent fatal," Nash-Ryder remembered. "I fell to the floor, was like a wet noodle, and I knew there was nothing I could do."
Nash-Ryder had heard of amoebas before, but thought they only lived in lakes, not rivers. And Uzel figured there were other, more deadly threats in the water.
"We always thought with her swimming out there that it would be an alligator or a water moccasin, or something like that that they were in danger of," Uzel said. "Not a single-cell organism."
That single cell organism attacked 11-year-old Will Sellars in the summer of 2007.
"He was just full of life," said his mother Peggy Vought. "Always happy, loved to do everything. Will was the kind of kid that just made everybody smile."
Vought says her life changed when her son went wakeboarding for the first time in July 2007.
"I really think the biggest thing that held him back was his fear of the water and gators and stuff," Vought said. "I never even mentioned that there could be other dangers in the water, he didn't know anything about that."
At some point on that fateful Sunday, an amoeba got in Will's nose and into his brain.
"He started vomiting, had a fever," Vought said. "He was starting to lose his sight. Cause when he came in he told his dad, dad where are you, I can't see you."
The following Wednesday, just a week and a half after first his wakeboarding experience, Will died.
"It was a nightmare, it still today is a nightmare, it always will be," Vought said.
A nightmare no one saw coming. Now Vought warns all parents that they need to take even the most minor symptoms seriously.
"If they know the kids have been in the water, keep an eye out and see. If they have a headache, if they're not feeling well, if they're losing their appetite, they feel like they have a fever, immediately get them tested."
An amoeba will cause flu-like symptoms; headaches, nausea, blurry vision, confusion, even hallucinations. The chance that an amoeba infects someone is remote, but the chance a person infected by an amoeba survives is less than that; there's only one known survivor in the United States.
The best way to keep kids safe from amoebas is to keep them out of lakes and rivers; any fresh water with a temperature of 80 degrees or higher. The other precaution parents can take is to make sure kids wear nose plugs while swimming.