ABSTRACT
This chapter is presented in the hope of providing an overview, and perhaps some degree of resolution of the question of the relationship between body temperature, henceforth “temperature” for short, and performance, particularly in the context of circadian variation. It was clear even by the turn of the present century that there must be some affinity between the 24-h curves of deep body temperature 214and performance. Just as performance in general was better during the day than at night (Patrick & Gilbert, 1896), so temperature was higher during the hours of normal wakefulness than during those of sleep (Baerensprung, 1851), even if the latter were spent awake (Woodhead & Varrier-Jones, 1916). It is only during the last 50 years, however, that there have been serious attempts to explore this correspondence in more detail by recording both temperature and performance in the same people during one or more 24-h periods. The result of these more recent activities has been an interesting series of pronouncements on the general question of the closeness of the temperature-performance relationship and the likelihood of there being a causal realtionship between the two. Let us follow the story through its changing phases.
