The freezing of biological material, such as cells and tissue, duing cryopreservation involves the interaction of ice in the extracellular medium with living cells. This cell-ice interaction critically determines the success of the cryo-preservation protocol, as measured by cell survival and viability after the freeze-thaw process. This paper presents numerical simulations of the response of a cell to freezing. The phase change of the aqueous salt solution outside the cell is computed using a sharp-interface technique. The cell is modeled as a salt solution enclosed by a semi-permeable membrane. We compute the concentration and temperature fields around a single cell in the presence of extracellular ice formation. Parametric variations in the factors affecting the cell-ice interaction are performed to describe the physics of thermo-solutal transport of the interaction. Cell water loss is quantified. The external ice front is computed for both stable and unstable (cellular/dendritic) growth modes. The results show that water egress from the cell is dependent on several controlling parameters in complex ways.