Important applications of bioheat and mass transfer include biopreservation (molecular, cellular and tissue) and thermal therapies (high temperature—laser, radiofrequency, microwave, high intensity ultrasound heating of cells and tissues, and low temperature—cryosurgery). These applications in turn support the growing fields of tissue engineering, cell therapeutics, drug stability and delivery, and minimally and non-invasive disease detection and treatment (i.e., cancer, cardiovascular and neural). The frontiers of biopreservation and thermal therapies are increasingly defined at the cellular and molecular level. This special issue focuses on these frontiers in areas of emphasis including thermodynamics (molecular and cellular stability), multi-scale mass transport (sub-cellular to tissue level transport), multi-scale heat transport (nanoparticle to bulk tissue heating), and extreme biology (anhydro and thermal physiology). The papers assembled in this special issue show the breadth of this activity with a series of invited reviews and original contributions in the area.