In a situation where many adults would have panicked, Joshua kept a cool head.
His parents had already taught him to recognise his mum’s symptoms and he went straight to a cupboard where sweets were kept knowing that she needed sugar to help her recover.
However, there were no sweets left.
Then the plucky youngster found a toy ambulance he played with which had the emergency 112 number on the side of it.
He picked up the house phone – which he had never used before – and dialled the emergency services.
He gave the call handler details of what had happened, told the operator that his mother was still breathing, that his father was out at work and that the house was locked.
Police rushed to the scene, got into the house through an open window and then paramedics arrived to treat Caroline.
Now Joshua has been awarded a Royal Humane Society Certificate of Commendation and been personally praised by Andrew Chapman, secretary of the society as a “superhero".
Mr Chapman said: “What he did was truly amazing.
"It was incredible for a five-year-old to do this, to do all he did and absolutely extraordinary the way he found the emergency services number.
"There is absolutely no praise too high for him.
"If he had not taken the action he took the possible outcome of this incident doesn’t bear thinking about. Joshua was a true superhero.”
Speaking after the ordeal, Caroline said her son was a “little hero” and his actions had been “unbelievable”.
After his heroics Josh was treated to a visit to his local police station.
Caroline said: “He loved it. He had been so excited for about a week beforehand.
"He was quite shy even more so at the police station because we obviously had quite high ranking officers there but he loved it.
“He got to sit in the police car and press the buttons for the sirens.”
The roots of the Royal Humane Society stretch back more than two centuries.
The Queen is its patron and its president is Princess Alexandra.
It is the premier national body for honouring bravery in the saving of human life.
It was founded in 1774 by two of the day's eminent medical men, William Hawes and Thomas Cogan.
Their primary motive was to promote techniques of resuscitation.
However, as it emerged that numerous people were prepared to put their own lives at risk to save others, the awards scheme evolved, and today a variety of awards are made depending on the bravery involved.
The society also awards non health care professionals who perform a successful resuscitation.
Since it was set up the society has considered over 87,000 cases and made over 200,000 awards.
The society is a registered charity which receives no public funding and is dependent on voluntary donations.
It was one of a select number of organisations to receive a donation from the Patron’s fund which was set up to acknowledge work done by organisations of which the Queen is the patron, to mark her 90th birthday.