An eight-year-old child is among those responsible for a "worrying" rise in hoax calls to Humberside Fire and Rescue Service.
The child made two inappropriate calls to crews in northern Lincolnshire and is now undergoing intervention to address their behaviour.
Making hoax and malicious calls is a criminal offence and can divert fire crews from real and potentially life-threatening incidents.
There were 142 hoax calls across the Humberside Fire region in the last financial year, a 40 per cent increase on the year before.
This year, the number of hoax calls currently stands at 58. Most tend to be made in the early morning or early evening.
Deputy Chief Fire Officer Niall McKiniry said: "Sending a significant amount of firefighters and appliances to what turns out to be nothing more than a hoax is, at best, frustrating and, at worst, deadly.
"The public rightly expect that we are ready to help them at a moment’s notice around the clock, but wasting time and money attending fictitious incidents costs seconds, if not minutes, which sadly can be the difference between life and death."
Anyone found guilty of making hoax calls can face a fine and/or up to six months in prison if convicted.
A spokesman for the fire service said: "There has been a worrying increase over recent weeks of hoax calls in our area.
"Humberside Fire and Rescue Service (HFRS) receives dozens of such calls every year, made from payphones, mobile phones and landlines. Malicious callers are not only an enormous drain on resources; their thoughtless behaviour endangers the lives and safety of the public."