By the differences in bodies and teeth.
Because the soil didn't have the same nutrients it has now due to lack of decomposition of other plants and animals.
Layers of the skin affected by the burn in this question are the epidermis and dermis. When a burn occurs to soft-tissue, the fragile, yet strong nerve endings enter in a "protective and chaotic" mode, trying to restore a homeostatic environment. There is also a massive attempt from the body to thermoregulate itself. The heat from the burn is causing the body to release excessive heat to prevent itself from over-heating. Until the brain is signaled to slow this process, heat will rapidly exit the body, thus the difficulty keeping warm
The answer is Glomerulonephritis, the patient would show data that suggest they have the presence of that disorder.
