Brake stuck on

[dh00001]

My rear drivers side brake is stuck on, the hand brake also feels slack but the passenger side is releasing.
It is currently -8 so I'm thinking this might be something to do with it? Any ideas about what it could be or how to free it?

 

[AlexGSi2000]

Could be a build-up of road salt / grit...

Try spraying some warm water over the brake callipers.

 

[dalegolf215]

hand brake cable corroded or frozen in its sleeve at a guess bout £10-£15 mate