Invention on Instagram: "A hand boiler is a sealed glass toy partially filled with a low boiling point liquid, most commonly alcohol, with a vacuum above it. When you hold the lower bulb in your hand, the warmth from your skin slightly heats the liquid and the trapped vapor inside. This temperature increase raises the vapor pressure, which pushes the liquid up through the narrow tube into the upper bulb, creating the illusion that it is boiling. Despite its appearance, the liquid is not truly bo