I feed my fish blood worms and brine shrimp frozen, but that is more for a time release reason. Shrimp and prawns are easy to thaw, and I always thaw mine before I feed my Aros. Just put them in a cup with luke warm water, or about the temp of your aquarium water. let it sit for a couple of minutes and your done. Don't use hot water or boiling water just because its the same thing as boiling vegetables, the majority of the nutrients leach out of the food and into the water.