American viewers were scared after KCAL-TV meteorologist Alissa Carlson collapsed on national television while she was about to deliver a forecast over the weekend.

Moments after she collapsed, a staff member of the show called 911 immediately and brought Carlson to the hospital.

The meteorologist said that she has been diagnosed with vasovagal syncope.

The New York Post reported that vasovagal syncope occurs when one’s body overreacts to certain triggers, such as the sight of blood or extreme emotional distress, according to the Mayo Clinic. It is often triggered by a sudden drop in heart rate and blood pressure, which leads to reduced blood flow to the brain.