I put them in ziplock bags and run them under very hot water and hold them down underwater while they are in bags if I want to get it done without having time to prepare. Otherwise, I put them in ziplock bags and leave them on the windowsill inside unti lthey thaw out and try to feed them ASAP. If I have to reheat them, I will quickly put them back under really hot water or heat them with a blowdryer to ensure that they are dry and hot.