This article reviews 82 papers that apply physiological measurement, otherwise known as biometric data collection techniques, in the fields of tourism and hospitality. It aims to reveal the key focus areas to which they have been applied to date, and how researchers have used these techniques in their attempts to contribute knowledge to the field. In doing so, we concentrate on how theory features in these works and critically discuss the role that theory tends to play in research that draws conclusions from physiological data. We find that the most common application of theory is to inform a study’s conceptualization, yet the majority of research to date focuses mainly on practical application. Seldom do hospitality and tourism researchers employing physiological measurement draw on the cognitive psychology and neuroscience theories, despite the insights these theories provide into the neurological and cognitive processes that underlie the data. This review concludes with a novel framework, embedded in cognitive psychology theory, that can be employed by researchers to enhance our understanding of the elicitation of emotion. While acknowledging the practical and informative value of physiological data, we urge researchers to consider relevant theoretical frameworks from both the neuroscience and psychology fields when attempting to draw meaningful conclusions from their data.