Cornish game hens are not actually a game bird, but a chicken bred for small size and meatiness. Because they are diminutive in comparison with regular chickens, even young fryers, it is handy to keep a few Cornish hens in your freezer. They thaw much more quickly than their conventionally sized cousins.
Remove the Cornish hen from your freezer 24 to 36 hours before it is needed, and allow it to thaw in your refrigerator. This is the safest method of all, because the bird is held at a food safe temperature for the entire time.
Place the packaged hen in a large bowl, and move it to your sink. Position the bowl so that it doesn't block the drain, and fill it with cold water. Reduce the flow of water to a trickle, and leave the bowl under the tap so that it is continually washed over with a constant stream of water. The hen will be thawed in approximately 90 minutes.
Microwave the hen on your microwave's defrost setting. Most microwaves offer defrosting by weight, which works better than the timed settings. Cornish hens are not well suited to microwave defrosting, because microwaves heat unevenly and the small birds are prone to becoming partially cooked. For best results microwave for about half the preset time, then switch to the water method.