Does putting hot water in a thermos bottle before you put coffee it help to keep temperature?

Yes, preheating a thermos bottle with hot water before adding coffee can help maintain the beverage's temperature for a longer period.

Here's how it works:

1. Thermal Insulation: Thermos bottles are designed to minimize heat transfer, keeping hot liquids hot and cold liquids cold. They achieve this through a combination of insulation materials, such as stainless steel or vacuum-sealed chambers, which create a barrier that reduces the flow of heat.

2. Warming the Bottle: When you preheat the thermos bottle with hot water, you essentially warm up the interior surfaces, including the walls and bottom of the bottle. This raises the temperature of these surfaces, helping to reduce the temperature difference between the hot coffee you'll add later and the bottle itself.

3. Reduced Heat Loss: By preheating the thermos bottle, you decrease the initial temperature difference between the hot coffee and the bottle. As a result, there is less heat transfer from the coffee to the bottle, and the coffee stays hotter for a longer duration.

4. Extended保温: The preheated thermos bottle acts as a more efficient保温 container. It minimizes the initial temperature drop of the coffee and slows down the overall cooling process, allowing you to enjoy your coffee at a warmer temperature for an extended period.