How does temperature affect the cell membrane?

Hint: All living cells are externally covered by a thin, transparent, elastic, regenerative and semi-permeable membrane called cell membrane. It is present in both prokaryotic and eukaryotic cells. It is now known as the plasma membrane or plasma lemma.

Complete answer:
The membrane is formed of lipids, proteins and carbohydrates. The liquid molecules are arranged in a bilayer in the cell membrane. Intrinsic or integral proteins are partially or completely embedded in the phospholipid bilayer. Structural proteins form the backbone of membranes and provide elasticity and mechanical stability. Enzymatic proteins regulate the cellular activities and carrier proteins help in the facilitated and active transport in the cell. The main carbohydrates reported in plasma membranes are hexoses, fucose etc. These are present as glycoproteins and glycolipids.
If body temperature increases during a high fever it affects the cell membrane and it becomes more fluid. The peripheral or integral proteins present in the cell membrane are damaged due to high temperature. Their tertiary and quaternary structures are affected which may lead to denaturation of proteins.
In case of low temperature, the movement of phospholipid molecules decreases which may lead to the formation of cracks between them in the cell membrane. The cell membrane loses its semipermeable nature and certain materials can get in or out of the cell through these cracks.

Note: The peculiar functional property of the plasma membrane is semi-permeable in nature. The membrane is primarily meant to regulate the exchange of materials between the cytoplasm and extracellular environment so that it can maintain homeostasis inside the cell.