Thanks to the technology available on Apple and Google phones, people can now receive pop-up notifications in some states if they are close to someone who has tested positive for COVID-19, writes CNN.
Alerts come through state health department apps that use Bluetooth technology to detect when you (or more precisely, your phone) have been in close contact with an infected person's phone.
While these apps may not keep you safe (they only let you know when you are exposed), they can prevent others from becoming infected if precautions, such as self-guarantee, are taken after receiving an alarm.
Millions of people are registering, even though these applications are not yet available in many states.
Health officials believe alerts can be especially helpful in cases where an infected person has been in contact with strangers, for example on a bus, train or cash register, who otherwise would not have known they were exposed.
How notifications work
For exposure notifications to be effective, Android users must enable Bluetooth and download their state notification app for Covid-19.
In these places, the phone notifies you when you are near someone
When someone has done the test and tested positive, they will be provided with a PIN to put on their phone. Any other phone near the phone with that PIN, usually within six feet or less, for at least 15 minutes, will receive an alarm telling the user to quarantine or notify a doctor.
The application assesses how close you were to the other person and how long this "contact" lasted.
