Parents are being reminded unconscious children and babies must always be put into the recovery position.
The prompt to mums and dads was issued after a study, published in the journal Archives of Disease in Childhood, found only 25% of parents correctly put their children in the right position after they had passed out.
Study author Dr Luigi Titomanlio from the Robert Debre Hospital in Paris said in 17% of cases, parents were putting their children in positions that were considered "dangerous".
Putting the child in the recovery position was associated with a 28% lower risk of hospital admissions.
Dr Titomanlio added, according to the BBC: "It is so simple to do. It's a simple manoeuvre that can be performed by even a six-year-old.
"What was really worrying was that some parents were shaking their baby. You can have brain damage from this, especially in children less than two years old.
"People should use the recovery position."
How to put someone in the recovery position
St John Ambulance's advice on the recovery position.
1. Kneel next to them on the floor, and place their arm nearest you at a right angle to their body, with their palm facing upwards.
2. Take their other arm and place it across their chest so the back of their hand is against their cheek nearest you, and hold it there. With your other hand, lift their far knee and pull it up until their foot is flat on the floor.
3. Carefully pull on their bent knee and roll them towards you.
4. Check that their airway is open, so they can breathe and any fluid from their mouth can drain away. To do this, tilt their head back, gently tilt their chin forward and make sure that their airway will stay open and clear.
5. Call 999 for an ambulance.
Researchers analysed 533 parents from 11 children's emergency care departments across Europe.
The children ranged from babies up to the age of 18 and had either passed out within the previous 24 hours or were unconscious when they arrived at the hospital.
Although 26% of parents (145 cases), correctly used the recovery position, 53% used other manoeuvres.
Children were shaken in 91 cases. Young babies were shaken in 25 out of 82 cases, and in 18 of these cases, the shaking was considered "potentially dangerous".
Alan Weir, head of clinical services at St John Ambulance, said, according to PA: "All people should learn the recovery position – it's very simple and can be the difference between life and death in an emergency.
"It's crucial that an unconscious but breathing person be positioned in a way that keeps them physically stable with their airway open."
Weir added: "For a child under the age of one, cradle the baby in your arms with their head tilted downwards.
"Holding them in this position will keep their airway open and stop them choking on their tongue or breathing in any vomit."