In early May, Justine Carter, 33, woke up feeling “tired and blah.” She hopped on her treadmill hoping that some cardio would boost her mood. But soon, Carter felt ill.

“I started to feel very nauseated,” the mom from Santaquin, Utah, tells TODAY.com. “I laid on the floor.

” As she felt sicker, she rushed upstairs to the bathroom and began vomiting violently. Then she called her husband, Kevin Carter, who put his mom, Teresa Carter, a nurse, on the phone too. Justine Carter lost consciousness at some point, so her 4-year-old son Tucker jumped on the call.

Tucker told the adults his mom fell asleep. “I said, ‘Tucker, I need you to wake your mama up,’” Teresa Carter tells TODAY.com.

“Tucker came back on the phone and said, ‘She’s sleeping.’” Justine Carter later learned she had a heart attack because of a spontaneous coronary artery dissection (SCAD), when a tear develops in the layers of an artery. It’s considered an emergency because it can prevent blood flow to the heart.

Justine Carter likely survived because her mother-in-law hurried over to provide CPR. “It’s a miracle I’m here today,” Justine Carter says. On May 3, Justine Carter woke feeling rundown.

But Utah gets long winters and she believed the overcast, cold day impacted her mood. She and her sister had been working out on their treadmills at the same time and connecting on the app Marco Polo to keep each other accountable. So, when her sister started her workout, Justine Carte.