The dog was walking on thin ice at a park when it suddenly fell through.
The man, Duncan McIver, didn't think twice, heading right out onto the ice.
Once he had 'Cosmo' in hand, they broke through the ice again.
But he didn't give up, eventually taking him back to dry land.
When he got out of the water, McIver called the decision 'split second', saying, "You're not just going to let him die, right?"
The whole ordeal was captured by a TV crew who was in the area to report on a story about ice safety.