CENTENNIAL, Colo. (KDVR) — Thursday, Jan. 30, was almost Daniel Mitchell’s last day. The 29-year-old was playing his weekly basketball game with friends in Centennial, Colorado, when he suddenly collapsed.

“I noticed when I was coming back down the court to play defense … I started feeling lightheaded and dizzy. Everything hit me at one time,” said Mitchell. “That’s when everything went black.”

It was a heart attack.

His group of friends quickly got to work. Merrill Redfearn, a dental student at the University of Colorado, put his CPR training to the test for the very first time.

“At first I thought it was a seizure until I went over there. He quickly stopped breathing and at that point, I just gave him CPR,” said Redfearn.

Mitchell’s other friend, Justin Dittmar, called for the automated external defibrillator.

“Merrill is doing chest compressions for five straight minutes. We’re trying to figure out how to use the AED shocking device as a group of people who came together in a span of 30 seconds,” said Dittmar. “He wasn’t breathing. He had no heartbeat. He seemed gone.”

Paramedics arrived moments later to help shock Mitchell’s heart back to life.

“I kind of figured it was something going wrong with my heart. For about a month and a half consistently, I was feeling some chest pains,” said Mitchell. “They weren’t enough for me to be too worried, but of course looking back on it I should have gotten checked out.”

Doctors told Mitchell that although he was young and healthy, genetics played a role in the scare.

“It was nothing I was doing to myself; it was genetic and hereditary,” said Mitchell.

In any case, Mitchell’s friends refused to give up.

“I am almost speechless,” said Redfearn. “To see a friend that you have played with for years be in that situation, and the first thing in my mind was, ‘I need to do the best that I can to help him.'”

It’s that type of quick-thinking that Mitchell is grateful for.

“Thank you from the bottom of my heart,” said Mitchell. “It was definitely a huge blessing to have you guys there. Without them being there, I mean honestly, I don’t know if I would be here today.”

Luckily, Mitchell was able to get help in time, but that’s not the case in every scenario. He and his friends hope this story is a reminder to get yourself checked to avoid something like this from happening to you.

Redfearn wants to send a reminder about learning basic life-saving skills as well.

“To people who have to be [Basic Life Support] certified or have to take a course, take it seriously,” said Redfearn. “You truly never know when it’s going to happen, who you’re going to have to work on. It could be you that may have to administer the help.”