Have you been procrastinating using your thumbprint as a way to unlock your iPhone? While for this mom, it was this security feature and the quick thinking of her 4-year-old son that saved her life.

After losing consciousness, this mother-of-three in Croydon, South London has her son to thank for getting help when she needed it most.

When 4-year-old Roman discovered his mother unconscious and not breathing, he used her thumbprint to access her iPhone and called emergency services with the help of Siri.

He told the call handler that he thought his mother was dead because "she's closing her eyes and she's not breathing".

The call handler calmly got Roman's address and asked him to go and shake his mother. "She's not waking up," he replied. "Give her a good shake, shout out "˜mummy'!" said the call handler. The boy can be heard shouting "Mummy!" and then told the handler that "it didn't work."

Thirteen minutes later, officers forced their way into the home where they found the boy, his twin brother and a younger brother inside with their mother who was laying unconscious on the floor.

After receiving treatments from paramedics, she was able to regain consciousness at home before being brought to hospital.