Critics of Tasers say the weapons are too dangerous and are responsible for numerous deaths. But in one incident in the U.S. an electric jolt from a Taser may have had the opposite effect when it brought somebody back to life, reports Science News.

A man in Connecticut was taken to hospital after he jumped into a freezing lake to avoid police.

The 40 minutes spent in the cold water gave him an irregular heartbeat, as revealed by an electrocardiogram test. This is a pretty dangerous condition that can lead to serious injury or even death.

The 28-year-old became agitated and started threatening hospital staff. Then security arrived and knocked the man out with a Taser.

He woke up minutes later. Subsequent medical tests showed the patient’s heartbeat had mysteriously returned to normal.

Tasers are not known for producing therapeutic effects of any kind. And doctors say it could be coincidence that the man’s heart returned to normal after the jolt. 

On the other hand, it could have acted as a defibrillation device, which uses electricity to treat a heart that goes out of synch.