Mountain rescuers in Cumbria are urging walkers who attempt three peaks challenges to keep updating emergency crews if they get into difficulties.
Scafell Pike is the highest mountain in England
It comes after a group of 11 contacted police when a number turned back while climbing Scafell Pike, but did not then call back to explain they were safe.
Wasdale Mountain Rescue Team was put on alert, but when nothing more was heard the rescuers were stood down.
A team spokesman said walkers should never call police on "a whim".
Thousands of people attempt the three peaks challenge during the summer, climbing Ben Nevis in Scotland, Snowdon in Wales and Scafell Pike in England - each the highest mountain in its respective country.
The challenge has grown more popular in recent years and has been increasingly criticised by conservation bodies and local residents, who complain of increases in traffic.
Cumbria's mountain rescuers are particularly busy during this period, and a Wasdale team member spotted 57 minibuses parked at Wasdale Head on Saturday night.
Richard Warren, the team's chairman, said: "Somehow we need to get the messages across that teams need to be well prepared and fit enough to complete the challenge.
"If they do get into difficulties you cannot just call the police on a whim and then carry on and finish the challenge without informing anyone that you are safely down."