Giving babies water can be very dangerous for their health, according to experts.
The advice only applies to babies younger than six-months-old, and it's because it could lead to a condition called hyponatremia.
The condition is defined by Mayo Clinic as occurring 'when the concentration of sodium in your blood is abnormally low', and happens when you drink too much water.
While the quantity of water you'd have to drink as an adult is very high, it's a lot smaller in babies - which is why giving water to babies could be dangerous.
Abbas Kanani, pharmacist at Chemist Click, told Yahoo UK: 'Kidneys are also too immature in infants under six and water can cause intoxication as a result of an imbalance in electrolytes such as sodium.
'This can cause hyponatraemia, which is where too much water has diluted the sodium levels of the body.
'This can cause complications such as swelling of the brain, seizures and, in extreme cases, death.'
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The condition can also affect their nutrition: 'Giving water to an infant can affect the baby’s ability to receive adequate nourishment.
'Their stomachs are so tiny and can fill up easily with water, making it difficult for them to get the nourishment they require.'
Katie Zeratsky, a dietitian at the Mayo Clinic, also added that giving a baby enough water to cause intoxication is unlikely, but not impossible.
She told Buzzfeed: 'Water intoxication is where you consume too much water in a short period of time and your blood level of sodium drops…making a tragic situation.
'In the adult world, you would have to push yourself past thirst and regulation to a point where you almost have to force intake.
'In terms of a baby, in most cases they would get too full to do this, so it would be more challenging to create this situation in an infant. It’s not impossible, though.'
General advice says babies should not be given water until they're six-months-old, as until then they get all the hydration they need from breast milk or formula.
