This volume has two broad themes: an examination of selected protein adaptations that support stress tolerance and an analysis of signal transduction systems, those critical links between the perception of stress and the activation of the co-ordinated metabolic responses that ensure survival. Several chapters deal with adaptive responses to environmental cold temperature and highlight novel advances in mammalian hibernation, low temperature enzyme function, cold-shock and antifreeze proteins, and freezing survival. Other chapters stretch out to explore biochemical responses to diverse stresses including water stress, mechanical stress, nutrient availability, oxygen limitation and oxidative stress. The integral roles of protein kinases, transcription factors, oxygen free radicals, and oxygen-sensitive ion channels in the detection and mediation of stress responses are explored. The multiplicity of responses is emphasized and shows us the vast potential of cells and organisms to respond to innumerable stresses, great and small, and the regulatory principles and mechanisms that are used to allow life to adapt and endure in every environment on Earth.