1. The hot dog is not completely thawed. If the hot dog is not completely thawed, the inner part of the hot dog may still be very cold, resulting in the hot dog not being hot inside. Before you prepare to grill a hot dog, you need to thaw it completely, either by leaving it at room temperature or thawing it in the microwave.

2. If you don't grill the hot dogs long enough, the inside part of the hot dog may still be cold. It is recommended to scald the hot dog with boiling water before putting it on the grill, which can accelerate the internal warming of the hot dog.

3, the quality of the hot dog is not good, some low-quality hot dogs may be the internal filler quality is not good, resulting in hot dogs inside not hot. It is recommended to buy good quality hot dogs, so that the filler inside the hot dog is of better quality, and it is easier to heat up when baking hot dogs.