When the body experiences extremes in temperature, then the body usually begins shutting down non-essential systems to life support and the individual goes into a coma. Coming out of a coma usually depends but not always on correcting the temperature extreme. High temperatures usually inhibit enzyme activity by denaturing the protein enzyme. The temperature will cause the protein shape to be so distorted that the active site is distorted to the point that the substarte is no longer accepted. Every enzyme functions within a pH range with an optimal pH within that range.
Enzymes are extremely sensitive to pH changes so their ranges tend to be rather narrow.
For example, the enzymes that catalyze blood chemistry must function within a tiny range of 7.35-7.45 in plasma. If the pH drops outside that range on the low end then a condition known as acidosis occurs and enzymes cease to function and the blood chemistry shuts down. On the other hand if the pH goes outside that 0.1 pH range on the high side, we have a condition known as alkalosis. If this should happen the structure and shape of the enzyme is altered so drastically that the active sites no longer can accept the substarte molecules because of their distortion. Changing the pH disrupts intramolecular binding forces that keep the enzyme in a specific shape.