One man's heart has bonded two California families together forever.
Mathieu Bergeron, 20, died suddenly in May 2017 when he fell while riding his over-sized skateboard - known as a longboard - and fatally hit his head.
"Almost overnight, I got what appeared to be a cold," Dr. Alsip told ABC affiliate KGTV.
But that "cold" turned out to be a heart condition that made it difficult for Dr. Alsip to walk and, sometimes, breathe.
The former lifeguard and polo player realized he needed a heart transplant and fast. He described feeling like he had "one foot in the grave" before Bergeron's death became his hope.
"When I was diagnosed a million years ago, I knew the day would come," Dr. Alsip told KGTV. "But when the day comes, it's just such a transformation that you can't express in words."
So Bergeron's heart now beats in Dr. Alsip's chest.
The organization Lifesharing, connected Bergeron's family and girlfriend with Alsip - first in a letter he wrote to them and ultimately face-to-face.
"Like when I read your letter, I was like, you're the perfect person to get it," Jessica Wallach, Bergeron's girlfriend, told KGTV about Alsip.
They not only got to meet him, but also to raise a stethoscope to their ears and listen to Bergeron's heart beating again.
"We'd always compare because mine wasn't as strong as his, and so, it still is really strong," Wallach said before bursting into tears.
Bergeron's mother couldn't stop thanking Dr. Alsip for agreeing to meet with them.
Visit the U.S. Department of Health and Human Services' website to find out more information on becoming an organ donor.