When you dig em,put them into a bucket of water as you dig,best on a not too hot a day...better in the morning /evening in hot weather. Dont keep any split/gutted worm in with the whole ones.
When home I put mine in paper for a day in the fridge in trays trying to not let em touch.
The next day remove any blown ones.
Then put them in the fridge in trays of water an inch deep,the water should be kept in the fridge first,plus have some spare water in the fridge(so its the same temp)
Check the worm daily/every other day and remove any dead ones.
Put the worm on paper daily(or every other day works for me with fresher worm)...empty n clean the trays and put in some fresh water ,put the worms back in (remove any that look blown first).Try not to touch the worm at all,more tip em gently.
The blow lug can be kept for weeks like this, the better the qaulity of the water the better the worms will be.
The worms can last weeks with no airator.
Any showing the first signs of blowing (not blown completely), can be gutted n salted,gut em,dry em,salt em ,remove excess salt,wrap in clingfilm and put in the fridge,theyll last months.