"This was the scariest moment I've had to imagine." Mum posts powerful warning.

A Canadian mum-of-two has issued a warning to other parents after being unable to wake her eldest daughter for almost 20 minutes earlier this month.

“This was my evening, this was the scariest moment I’ve had to imagine,” Jennifer Abma in a Facebook post earlier this month.

Alongside the message was a photo of her young daughter Anastasia in bed, covered in sweat and flushed dark pink.

"This is severe heatstroke. There is nothing scarier than not being able to wake your baby up. This is clear proof a child doesn't need to be in the sun to get heat stroke."

Abma continued, saying it took a full 20 minutes and help from emergency ambulance staff to wake up her daughter, who had taken herself off for a nap earlier that afternoon.

"I had no idea how hot her bedroom was until I went to wake her up soaked in sweat, red face, boiling and unable to wake her." 

When the ambulance staff were eventually able to resuscitate Anastasia, they discovered her blood sugar levels were at just 1.2, where they should have been above 4.

"No it is not my fault this happened to her but it is hard not to blame yourself, this is a lesson learnt & hopefully other parents can take something from this & make sure you are checking the rooms in your house because thy can be as dangerous as a hot car," Abma wrote.

"Still I'm shook and I can't imagine what would have happened if I didn't go check on her." 

Since telling her story two weeks ago, Abma's post has been shared more than 45,000 times.

"I'm so glad shes [sic] okay.. holy hell! Even the picture is terrifying!" one Facebook user wrote.

"So happy she's ok," another agreed.