Hen has been off eggs (17 days) they have gone cold:(

[AdiVic]

Hello

Our very reliable broody got locked out of her broody coop this morning by my husband (GRRRRRR!!!!!) She has been off her eggs for 8 or 9 hours at worst. The eggs feel quite cold. I've locked her back in, but is there much hope? Day 21 on Monday. Bloody husband!

Any tips gratefully received

If they have gone cold to the touch then it is very unlikely that they will hatch I am afraid. there is nothing that you can do about that as the chicks die in the shell (sorry sounds brutal - poor you). wait until day 24 or 25 and if nothing has happened you will need to clear them out and start again. if the weather is warmer then there is sometimes a chance this is why I always give an extra couple of days in case the hatch is delayed and they are still going. good luck don't be too cross with DH he probably feels terrible and its easy to do by accident.

I thought they can survive 12 hours or so cold...

They may surprise you, sometimes they survive longer than you would think without heat. I would candle them and see if there is any movement. Fingers crossed!