A small portable heating device that uses charcoal as fuel and is used inside snow globes in cold regions.
There are various types, such as a truncated cone shape with a window, a rectangular parallelepiped, and a bowl shape.
Be careful of carbon monoxide poisoning due to incomplete combustion, and be sure to provide ventilation.
Carbon monoxide binds to hemoglobin in the blood more strongly than oxygen and cannot be separated,
much like a yandere.
This makes it impossible for red blood cells to carry oxygen.