There's a process you want to follow called 'hardening-off' which is always used by tomato growers to reduce shock.
When plants are first set outdoors, it is into a sheltered location, ideally a cold frame, and it is left open only during the warm part of the day for the first week or 2. This lets the plants get used to the cold night air gradually.
Another thing that cannabis growers need to consider is photoperiod stress. Try to keep your plants on the same schedule of light/dark every day. If you cannot guarantee a good schedule, keep a light- even a single CFL- on them all the time just to maintain a 24/0 schedule.