There are several ways to keep your German Shepherd warm in the winter:

1. Keep your dog indoors as much as possible. German Shepherds are a breed that is well-suited to living inside with their human families.
2. Provide your dog with a warm, dry place to sleep. A dog bed with a waterproof, insulated bottom will help to keep your dog warm and dry.
3. Make sure your dog has plenty of blankets and towels to snuggle up in. You can also invest in a heated dog bed or pad to provide extra warmth.
4. Consider getting your dog a coat or sweater to wear when you take them outside. Look for one that is made from a water-resistant and windproof material to keep your dog dry and warm.
5. Keep your dog well-groomed during the winter months. A thick, healthy coat will provide insulation to help keep your dog warm.
6. Make sure your dog has access to fresh, unfrozen water at all times. Dehydration can be a problem in the winter, especially if your dog is spending a lot of time outside.
7. Limit your dog’s time outside in extreme cold or inclement weather. If you do need to take your dog outside, make sure they are properly dressed and only stay out for short periods of time.