Mountain rescuers have urged holidaymakers not to climb England's highest peaks in the Lake District following a surge in "avoidable" callouts.
Keswick Mountain Rescue Team says it has seen a "tidal wave of avoidable rescues" over the last week, with 19 callouts since 24 July.
Eleven of them were "truly avoidable" and involved "inexperienced and ill-prepared walkers finding themselves in serious, life-threatening trouble", the team wrote on Facebook.
"Staycation holidays are introducing a new type of visitor" to England's national parks - a problem that is also being felt in north Wales, they said.
One rescue last Saturday saw five teams scrambled to Scafell Pike, the tallest mountain in England, after a family-of-three tried to scale it despite forecasts warning of "atrocious" conditions.
It took 12 hours to get the family to safety, the team added.
Coronavirus travel restrictions have resulted in more families opting to stay in the UK for their summer holidays and have led to a surge in bookings across Britain's beauty spots.
But the Keswick team says holidaymakers are trying to climb mountains relying solely on smartphone mapping technology, which soon runs out of power and provides no back up.
People are also ringing 999 on their last 1% of phone battery, which means they often get cut off before they can give their details to police, making rescue missions longer and more complicated.
Warning that the recent number of rescues is "unsustainable", mountain rescuers said: "Exercise within your limits and avoid taking risks.
"Know your level of skill, competence and experience and those of your group.
"Learn how to navigate, take a waterproof map and a compass, don't rely on smart phone technology, it can let you down.
"Take a torch, even on the longest days, you never know when your activity will catch you out. Take a power bank battery charger it will save you a lot of grief plus allow you to take even more of the memory photos."