| T0 | The temperature of the rod at x = 0 |
| T(x) | The temperature of the rod as a function of x |
| Tenv | The temperature of the air, room temperature |
| Theta(x) | The "excess" of the temperature above room temperature. T(x) - Tenv |
| SA | The cross sectional area |
| C | The circumference of the rod |
| k | The thermal conductivity of the material of the rod |
| h | The surface coefficient of heat transfer between the rod and its environment |