The fire service receives thousands of hoax calls every year, and more and more of them are being made by young people.
Now one fire service has had enough and is introducing tough new punishments for children over 10 who make prank calls.
We sent Leah to find out more...
"When someone dials 999 for the fire service you'd definitely expect them to arrive at the emergency as soon as possible, right?
So I was really surprised to find out that one fire service in Cambridgeshire is having big trouble with hoax callers.
I was given special access to a call centre where operators work through the day and night taking calls from the public and sending out fire crews to tackle blazes.
While I was there, several people called in to report fires and the operators were calm and collected. One person rang in to report that a car was set alight.
Once the phones stopped ringing and things got a bit quieter the operators told me that although most people call up with real problems, since the start of the year they've been getting hundreds of jokes calls from kids as young as 10.
This all has a big impact on the firefighters who get sent out.
Leah had to wear the right gear to take part in a practice drill
My next stop was to the local fire station to find out exactly what it's like for firefighters... They gave me some fire boots, a jacket and a yellow helmet to take part in a practice drill.
When the bells start ringing you have to get ready as soon as possible and jump into the truck.
It usually takes the crew about 20 seconds to get everything on. It was pretty high energy and you don't have much time to think.
They told me it's pretty frustrating when they rush to an area and there's actually no fire. If they're busy travelling to a fake fire, they're not able to cover the real emergencies.
They're worried that young people don't realise that all calls have to be taken seriously and there's no way of knowing if the emergency is real.
Leah races a fireman to kit up
So they've made a DVD to help explain that prank calls can cost lives.
But the plan is to also pass on details of any calls they reckon are fake. And even if the person is as young as 10, they'll be passing on their details to the police.
They're hoping this will put off any would-be hoaxers, so they can get on with their job."