A Delaware student was saved from a potentially fatal carbon monoxide poisoning after getting alerted by her Apple Watch.

CBS News Philadelphia recently reported how Natalie Nasatka, a student, sent out an Emergency SOS using her Apple Watch before passing out from carbon monoxide poisoning. The report said that Nasatka had experienced symptoms associated with the poisoning, such as dizziness and lethargy, and somehow managed to use the feature to contact emergency services.

Once alerted, the local fire department arrived and saved her. The authorities said that carbon monoxide levels had reached 80 parts per million, which was ‘dangerously high.’ A faulty heater was said to be the culprit in the leakage of the toxic gas, and Nasatka mentioned that there wasn’t a carbon monoxide detector in place.

Apple Watch models have an Emergency SOS feature that calls emergency services using the Side button, such as 911 in the US and all registered emergency contacts.