A detailed knowledge of surface temperatures is vitally important in many fields of science and engineering. Thermochromic liquid crystals have become widely accepted over the past decade as a simple, low-cost, and accurate tool for temperature measurement, but their potential in biological surface temperature monitoring or heat production, or biomechanics, has not been fully exploited. In this paper, the principles and practice of using liquid crystal thermography for noninvasive temperature measurement are discussed. Types of liquid crystal materials, their application to surfaces, chromatic interpretation, and associated advantages and limitations are summarized. Finally, the application of liquid crystals to particular fields of interest in biomedical engineering is reviewed and potential applications are identified. Based on this review, the suitability of using liquid crystals in medical applications is assessed.