🌡️ How a Thermos Flask Works
🏺 Double-Wall Glass Container
Inside the thermos, there is a glass container with TWO walls creating a special space between them.
🌌 Vacuum Space (No Air!)
The space between the two walls has NO AIR (vacuum). Without air, heat cannot travel through by conduction or convection - blocking heat transfer!
✨ Shiny Silver Surfaces
The inner surfaces are silver and shiny. These mirror-like walls REFLECT heat back, preventing heat loss by radiation.
🔒 Insulating Stopper
The lid/stopper is made of cork or plastic - insulating materials that stop heat from escaping through the top.
🛡️ Insulating Bottom Pad
A special pad at the bottom prevents heat from transferring to the surface below.
🔐 Protective Outer Case
Metal or plastic covering protects the delicate glass inside and provides durability.
🎯 Result: Temperature Lock!
By blocking conduction, convection, AND radiation, the thermos keeps hot drinks HOT and cold drinks COLD for hours!