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His family thought he had a cold. A couple of days later, he died of the flu.

Here's a look at how the flu virus infects the body and produces symptoms. (Video: Joyce Koh/The Washington Post)

Like many flu-related illnesses, Dylan Winnik's started with a cold — and escalated rapidly.

He had it for a couple of days. By Monday, he was feverish. By Tuesday, his temperature had gone back to normal, but he died that day.

The 12-year-old Florida boy became the latest casualty of an intense flu season that has so far resulted in thousands of hospitalizations and deaths of 2½ dozen children nationwide.

Dylan's father, Sergio Winnik, did not want to be interviewed Thursday, according to the father's cousin. Winnik told the South Florida Sun-Sentinel earlier that his son had fever and chest pain, but he still went to school on Monday. The seventh-grader didn't go to school on Tuesday, when Palm Beach County sheriff's deputies were called to his father's home in West Palm Beach, the Palm Beach Post reported.

Dylan's stepfather, Mike Medwin, told NBC affiliate WPTV that family members checked the boy's temperature on Tuesday. It was normal, at 98 degrees Fahrenheit. He died a couple of hours later.

“Don't mess around with the flu,” Medwin told the TV station. “It's not going to somebody else. It can happen right in your neighborhood. Right in your name. It happened to us. Lighting struck.”

Autopsy results are still pending, but his family said they've been told the boy died of the flu.

Medwin, who was not immediately available to comment Thursday, has started a GoFundMe page to help pay for Dylan's memorial and funeral.

“There is nothing that can ever explain the loss of a beautiful child at such an early age. Dylan was highly intelligent, surprisingly funny, and always full of life busy with his two brothers,” Medwin wrote on the  page.

In a letter sent to parents Wednesday, Okeeheelee Middle School Principal David Samore said Dylan will be missed by students, parents and staff.

The Florida Department of Health said three children, all of whom were not vaccinated, have died as a result of the flu this season. That number does not include Dylan. A spokeswoman said the agency does not have information on his death. Dylan also was not vaccinated this year, Medwin told local media outlets.

Here's what you should know about the flu season this year

This year's flu season is already the most widespread on record since health officials began keeping track 13 years ago and has resulted in more deaths than what would be expected at this time of the year, The Washington Post's Lena Sun wrote. The majority of those hospitalized are older people and young children.

Thirty children have died as a result of the flu, and more than 8,900 have been hospitalized since the season started in October, according to the Centers for Disease Control and Prevention's latest report released earlier this month. These numbers do not include Dylan, who died after the weekly report was released.

Nearly the entire United States, except the District of Columbia and Hawaii, along with the territories of Guam and the U.S. Virgin Islands, are seeing widespread flu-related incidents, according to the CDC. Flu seasons from at least the last decade weren't nearly as bad, with a majority of the country mostly seeing only sporadic flu activity.

Flu viruses are most common during the fall and winter months. Flu-related incidents often begin to increase in October and November and peak between December and February. The season can last until May.

Less than two months ago, a young bodybuilder from Pennsylvania died shortly after he came down with the flu. Kyler Baughman's mother told local media that he came home for the holidays with a runny nose and thought he simply needed to rest. But his coughing became worse, and his fever didn't subside after Christmas. He died on Dec. 28 of “organ failure due to septic shock caused by influenza,” his mother told NBC affiliate WPXI.

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