[peskypixie]

 Looking very dry and curled up - only alternative now is central heating, too much of a shock? or should I leave them where they are and hope they survive? We have been down to -7 degrees so far, really cross with myself for having forgotten about them since the 'big freeze'.   

[SG6]

The lemon may survive (it is a "may" not a will) but I doubt if the orange will.
If you have a room that is not directly heated then I would suggest that they are placed in there. Then keep them in until around April as moving in and out at short notice will not help them either.

It may be a shock but to leave them out is I suspect a certainty, especially for the orange.

If they come inside make sure they get water. They will lose leaves owing to the temp change, well mainly the humidity change.

Wish you luck.

[peskypixie]

Thanks SG6 will bring them in - fingers crossed!