Add circles, triangles, squares or rectangles. Each keeps the conductivity selected when it was created. Hold a shape in the flame near the top center and watch the hot spot spread. Touch it to a cooler shape to transfer heat.

A fixed infrared scale keeps colors comparable: purple and blue are cool; red, orange, yellow and white are hot. The tank continuously loses heat to the room. The torch heats exposed surfaces; another shape can shield the flame.

This is a qualitative model: equal heat capacity per grid cell, conservative internal and contact heat exchange, approximate nearby radiation, air cooling and rigid-body collisions. Conductivity is a relative 1–100 setting, not a measured material constant. Displayed temperatures are illustrative °C. No melting, fluid flow or thermal expansion. Up to 32 shapes.