[13] In 2018, Hamlin led the Panthers "sniper gang"[12] secondary with 77 tackles and two interceptions as a redshirt sophomore and was named honorable mention All-Atlantic Coast Conference (ACC).

[14] Going into his final season in 2020, Hamlin was a team captain and was named to the All-ACC second-team after leading the Panthers with 66 tackles and seven passes broken up.

[28] On January 2, 2023, during a Week 17 Monday Night Football game against the Bengals, Hamlin collapsed on the field at 8:56 p.m. EST after tackling wide receiver Tee Higgins and required immediate emergency medical treatment.

[29] At the start of the play, Higgins caught a pass by Joe Burrow near the 50-yard line and ran downfield while leading with his right shoulder, which collided against Hamlin's chest.

Later that night at 1:48 a.m. local time,[43] the Bills reported that Hamlin had initially suffered cardiac arrest and his heartbeat was restored on-field.

The same day, the Bills released a statement, saying, "Damar has shown remarkable improvement over the past 24 hours" and "while still critically ill, he has demonstrated that he appears to be neurologically intact.

Trauma surgeon Timothy Pritts said Hamlin was able to communicate by writing on paper or by nodding and shaking his head, since he still had a breathing tube.

[50] When Hamlin woke up, he was able to follow commands, had full control and feeling in his extremities,[51] and asked who won Monday night's football game by communicating in writing on a clipboard.

[53][54] The next day, Hamlin made his first public comments since his cardiac arrest through social media, stating that he was thankful for the love he has received and asked for continued prayers for a "long road" ahead.

[55][56] On January 9, a week after being admitted to the hospital, Hamlin was discharged from the University of Cincinnati Medical Center so he could return to Buffalo and continue treatment there.

[64] In February 2023, Hamlin made a special on-field appearance at Super Bowl LVII, accompanied by Bills athletic training and UC Health staff members.

[71][72] On April 18, 2023, Buffalo Bills general manager Brandon Beane stated that Hamlin was fully cleared to return to the NFL.

[83] Shortly after the incident, there was an increase in rhetoric and disinformation from well-known anti-vaxxers, including Charlie Kirk and Drew Pinsky, making unfounded claims about Hamlin's cardiac arrest and COVID-19 vaccines.

On May 15, 2023, Hamlin received the George Halas Award that is given annually by the Pro Football Writers of America to the NFL player, coach, or staff member who overcomes the most adversity to succeed.

[91] On August 12, 2023, Hamlin played his first NFL snap since his cardiac arrest in the Bills' preseason opener against the Las Vegas Raiders.

[93] On October 1, he was activated for the first time since his cardiac arrest in week four against the Miami Dolphins, serving as a backup after Jordan Poyer was ruled out due to an injury.

[95] On November 13, Hamlin played his first snaps on defense and made his first tackle since the on-field incident during the fourth quarter of the Bills' week ten game against the Denver Broncos.

[105] In the hours following his in-game collapse and medical emergency in January 2023, Hamlin's 2020 GoFundMe campaign for the Chasing M's Foundation toy drive received a massive influx of donations from fans and others.

[106][107] In the days that followed, dozens of NFL players, coaches, and executives donated to the campaign,[108][109][110] which grew from its $2,500 goal amount to over $8.7 million as of January 12, 2023[update].

On January 12, The Buffalo News had a detailed story covering the enormous changes facing Chasing M's structure and operations in light of the large donations, including its tax-exempt status and governance.