I have a hot water bottle that I use occasionally in the winter months. Filled with boiling water it'll be too warm to handle for about 45 minutes, then comfy f

I have a hot water bottle that I use occasionally in the winter months. Filled with boiling water it'll be too warm to handle for about 45 minutes, then comfy for hours. Tucked under the comforter it's frequently still a little warm in the morning.