Heat waves are lethal and cause a disproportionate number of deaths in the elderly relative to any other age group. Although gastrointestinal barrier dysfunction is a primary cause of heat related illness, little is known about the effects of aging on gastrointestinal barrier function during hyperthermia. The central hypothesis of this work is that the elderly exhibit greater gastrointestinal barrier dysfunction during hyperthermia. Participants will complete a control trial where gastrointestinal permeability (without heating) will be assessed in young and older adults. In the experimental trial, controlled hyperthermia will be achieved using a water perfused, tube lined suit. Core body temperature will be raised to a maximum of 2 degrees Celsius above the baseline value, or an absolute temperature of 39.5 degrees Celsius. Comprehensive assessments of gastrointestinal barrier function, microbial translocation and systemic inflammation will be assessed in young and older adults. The expected outcome of this work will re-shape out understanding of the consequences of aging on gastrointestinal barrier function during heat waves.
The purpose of this study is to assess the gastrointestinal responses of the elderly during hyperthermia.