"I just thought, 'Just a flu, he'll get over it,'" Sergio said. "And he never really did."
Instead, Adolfo got worse -- with headaches and a lack of energy. A week after his symptoms appeared, he was airlifted to the UC Davis Medical Center from a Chico hospital.
"His heart function was very low," Dr. Amy Rahm, an assistant professor of pediatric cardiac surgery, told FOX40. "We knew that we were on borrowed time."
It turns out that the otherwise common cold had done something uncommon. It had attacked Adolfo's heart muscles, leaving him in danger of cardiac arrest.
"It's not common at all, but when it does happen it is life-threatening," Rahm said.
Adolfo was rushed into surgery but because his heart was beating so fast, he could not be sedated. He had to be awake for part of his procedure.
"I just kept asking if it was over," Adolfo said.
But during that surgery, Adolfo made U.S. history. Surgeons installed an Impella, a pump that allows his heart to move blood normally. Adolfo is the youngest person in the U.S. to have one installed.
Today, Adolfo is doing much better and looking forward to getting back to normal.
"I just wanted to be back swimming," he said.
But his dad says this should be a warning to other parents when their kids come down with a common cold.
"Keep a close eye on their kids," Sergio said. "Something as small as the flu could turn into something else."