Curly cucumber leaf......

Evening.  Can anyone shed any light on this for me.... my cucumber plants ( from seed) are doing really well about 3" tall now, but the leaves ( on a couple) have turned in.  Any idea why?  will they survive? Im a bit attached to them having brought them into the world.

You may get them to survive if you bring them in at night and then put them out into the greenhouse during the day.  You may have to do this for the next few weeks until the night temperature is sufficiently high to stop the cucumbers from getting a chill.   If they do survive and put on growth then you will need to pot them on.

thanks for your advice - seedlings are actually in my conservatory so can only assume temperature has been dropping too much at night, although have to say everything else seems to be doing ok ( beans, peppers),  I'll turn up the thermostat