A group became benighted on Esk Pike. The initial call went to Wasdale MRT who were happy to pass it to us! They were recovered from Ore Gap and assisted down, cold and wet but unhurt
Ask yourself three questions
Do I know what the weather will do?
Do I have the right skills?
Do I have the right equipment?
What ever time of year, always carry a torch. You never know when or why you may be delayed.
When it goes dark in the hills, it usually goes VERY dark! There's little ambient light unless you are lucky to be out when there is a good moon and little cloud.
It's worth carry a set of spare batteries as well. If you're lucky they'll be the same size as other devices you might be carrying such as GPS.
Modern LED torches are very reliable, and batteries last a long time, and it's well worth considering a headtorch in favour of a hand torch, leaving your hands free.