Rescuers in Northumberland reminded hill-goers to plan their outings to take account of shortening daylight hours as British summer time ends.
Northumberland National Park Mountain Rescue Team and North of Tyne Mountain Rescue Team warned it may take longer to reach casualties in the dark.
Outdoor enthusiasts should remember to take a torch and spare batteries, and not overreach themselves, the teams said.
Iain Nixon, team leader for Northumberland National Park team, said: “Before anyone sets out for an adventure, remember that you’ll have fewer daylight hours and you can expect it to get dark more quickly.
“This means you really should be carrying a torch and spare batteries.
“When teams respond to a call out at night, it can take us longer to get to people. This means that casualties will be sitting out in the cold for much longer.”
Keith Briggs, team leader for the North of Tyne team, also advised that hill-goers to carry enough warm clothing and spare food or a hot drink as temperatures inevitably start to drop.
“We really want people to be adventure smart and follow the advice on the Adventure Smart website. Plan your activity based on the amount of daylight you’ve got and your ability level,” he said.
The teams urged hill-goers to make sure that they carry a map and compass as a back-up to any mobile or GPS based device and to know how to use them.
The two leaders said: “Mobile phones with mapping software can be a great addition to your navigation toolkit, but don’t rely on them and have a plan in case they run out of power or signal.
“Always carry a torch and whistle and know how to attract attention with them. This is particularly important as we head into the winter and we have much shorter days.”
The Northumberland teams said, if you do get lost or injured in the hills, moors and forests and are able to call for help, you should dial 999, ask for police and then mountain rescue.
If you are able to give your exact location as a grid reference from a map or an app such as OS Locate, this will greatly assist. They added that a What3words location will help.
British summer time ends at 2am on Sunday, when clocks go back an hour. Sunset time for Rothbury on that day is 4.42pm.