TikTok has been responsible for all kinds of crazes over the last year or so.
But the latest has left firefighters having to issue a warning as teens have been getting stuck in toddlers' swings.
And while the temptation may be there to relive your childhood by squeezing into a swing and capturing it on camera, the message is - don't.
London Fire Brigade (LFB) has said it had responded to 21 instances of people trapped in swings this year – all linked to the challenge on the video-sharing app.
Twelve incidents took place in the past month alone.
The bizarre trend sees teenagers attempt to force themselves into the swings’ metal frames.
In one call out, firefighters were sent to Ruislip in north-west London on Saturday to help a 14-year-old girl stuck in a swing.
Crews had to dismantle the swing and use pressure to expand it around the girl so they could free her.
LFB said the firefighters involved were "conscious they were being filmed by the girl’s friends but they hadn’t previously been aware of the challenge".
Fire services across the UK have spoken out about the number of calls they have received to assist people in similar situations.
They are urging teenagers to think twice before taking part in the challenge and wasting firefighters’ time.
LFB’s assistant commissioner for fire stations, Jane Philpott, said: "Our firefighters attend a wide variety of challenging incidents and far be it from us to judge the precarious positions some people find themselves in.
"But in their quest for TikTok fame, people have been potentially diverting our crews from more serious incidents and that isn’t something we want to see.
"Each job our firefighters do attend takes time and we are hoping to prevent further callouts to such incidents by issuing this warning.
"We would ask people to please just think twice before taking part in this challenge – think of the injuries you could cause yourself, the damage to the swings which have to be cut apart, and most of all the fact you’re tying up resources which could be needed for a genuine emergency.
"It might be a fun story for your friends, but wasting the time of emergency services is serious."
