Police are warning rock fans at this weekend's Download festival about the potential for accidental calls while in the mosh pit.
Leicestershire Police issued an alert ahead of the event at Donington Park, which begins on Friday.
Posting on Facebook, the force said, in previous years, they received "a rise of nearly 700 extra 999 calls" caused by energetic dancing at Download.
"The tech assumed that people in mosh pits had been in a collision, causing 999 contacts and abandoned 999 calls," said the post.
Police have blamed mobiles and wearable gadgets featuring technology which alerts emergency services when it suspects there has been an accident.
The technology can inadvertently activate when hardcore rock, heavy metal, or punk fans are involved in aggressive styles of dancing - sometimes called "thrashing", "slam dancing" or "pogoing".
Certain iPhone and Apple Watch models operate a "crash detection" feature - turned on by default - which is designed to identify a severe car crash and connect people to emergency services.
Even if people are unaware that the feature has been activated, the device will call the emergency services automatically after a 30-second countdown.
Some Android mobiles operate a similar service called "car crash detection".
"All those calls had to be assessed, with three outbound call attempts completed to ensure there is no threat, risk or harm, taking our contact handlers away from answering true emergency calls," police added.
They recommended switching on airplane mode or disabling emergency alerts on wearable tech, as well as answering any callbacks so officers know fans are safe.
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Some of the reactions to the post included "don't mosh too hard" and "be wary of the mosh pit".
But another user commented: "Avoid false alarms and allow police to focus on crime."
Headline acts at Download are Green Day on Friday, Sleep Tolken on Saturday and Korn on Sunday.
(c) Sky News 2025: Police issue mosh pit warning ahead of Download festival in Leicestershire this weekend
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