I recently expanded my hive to the second deep by baiting up two frames from the lower deep up.I'm wondering about chilled brood it has been raining here in "Seattle" New Jersey for about four out of every seven days and overnight temps are in the low to mid 60's. I know factors include colony size amount of brood to warm etc.
I have been using this technique for years and haven't had problems with it if thought is put in behind it. 60 degrees is fine! Even in the 50's can be OK. You don't want to do it in the early spring or late fall however. Try to move up frames that have emerging bees if possible. Done without thought or care you could run into chilled brood.