The US mum learned this the hard way when she did it herself and her daughter ended up with a broken leg. Now, she shares her story in the hopes others won’t make the same mistake.
And in case that written warning isn’t enough to scare parents out of it, she has stomach-turning photographic evidence.
Heather said in her post this week that in 2015 she went down a playground slide with her then-one-year-old daughter Meadow on her lap and the little girl's foot got caught between her mum and the slide.
"This picture is the moment her leg was breaking," Heather told her followers of the image. "She’s still smiling... because it was happening at this exact moment."
The mum-of-three said she was surprised to learn from the not-so-sympathetic doctor her daughter saw, that this was a common injury.
So common in fact that the American Academy of Pediatrics released a statement last year warning parents against sliding with their kids.
"An estimated 352,698 children less than six years of age were injured on slides in the United States from 2002 through 2015, and many of those injuries were leg fractures."
However, Heather said she had "no idea".
"I thought everyone took their kids down the slide," she recalled.
Heather said she believed there should be warning signs at playgrounds, but because she had never seen one, she decided to share her own "public service announcement".
"I share this picture every year in hopes that the pain Meadow felt and the guilt that I still feel will save other babies and parents from the same.
"Don’t ever go down a slide with a baby on your lap. There is no safe way to go down a slide with your little one."
It's also a good idea for parents to avoid letting their children play wearing necklaces.
Last year NSW girl Phoenix Clucas, then seven years old, was almost strangled to death when her necklace got caught on a slide at a friend's birthday party.
She suffered severe injuries, but thankfully was saved. However, as The Sydney Morning Herald reported in June 2017, many Australian kids aren't so lucky.
More than 55,000 children were hospitalised due to falls from playground equipment between 2002-2012.