Frosty bike won't change gear

[Jezston]

This is odd... Bikes been through colder in the last few weeks but came out to the bike shed after work to find the bike covered in frost and it won't change gears!

Any ideas what's caused this and how I can fix it?

 

[PaulSecteur]

Inner cables frozen to the outer cables, or the pivots on the derailer frozen in position?

Have a look to see where the cable goes slack when you inex the gears.

 

[Jezston]

seems a warm train journey was what was needed ... Second leg of the journey and it gradually came back to life. Drenched it in lube and left it indoors so should be totally fine tomorrow!