The American Heart Association is urging the public to be aware of deadly “holiday heart attacks,” as research shows more cardiac deaths occur during the last week of December than any other time of year.

Factors like winter weather, stress, overindulging, and delaying treatment all play a role. Dr. Saura Fortin says ignoring symptoms is critical, urging people to seek prompt treatment.

The AHA also encourages learning Hands-Only CPR, noting most cardiac arrests happen outside the hospital.