The substance that is part of the medium inside and outside your cells, that carries nutrients to, and waste products from cells, that maintain body temperature, and acts as a lubricant and protective cushion is:

Water

Explanation:

Thanks to selective permeability (the ability to determine which substances enter and leave the cell), water can move in and out of cells as needed to regulate osmotic pressure.

Water is also an essential component of blood plasma, capable of transporting oxygen and nutrients to cells.

Water also carries metabolism products throughout the body until they are excreted. In addition, water plays a key role in regulating body temperature through sweating.

It also acts as a lubricant, preventing friction between bones, joints and internal organs, providing protection to various body structures.

the answer is cell division : )