The effectiveness of evaporative cooling vest with ventilation fans on the thermal state of persons with paraplegia during exercise

Abstract

Persons with paraplegia (PA) are prone to thermal strain due to impaired thermoregulatory responses at body segments below injury level. The use of evaporative cooling vest (ECV) incorporated with ventilation fans (hybrid vest) is proposed to enhance heat losses at the limited sensate trunk skin area. This study developed a 1-D transient mathematical model for the hybrid vest and integrated it with a PA-bioheat model to predict body thermophysiological responses. The hybrid vest model was validated via experiments performed on a heated plate. A parametric study was then performed using the integrated models at ambient temperature, Tamb, between 28 and 36 °C and relative humidity, RH, at 30 and 60% for moderate (3 met) and high (6 met) activity levels sustained for 1 h. Evaluation of hybrid ECV performance for persons with PA was based on the drop in local sensate skin, and sensible and latent heat losses, compared to No-Vest case. The simulation results showed that the hybrid vest did not reduce skin temperatures significantly compared to No-Vest case at 3 met, since no sweating was present. At 6 met, however, the hybrid vest resulted in a significant drop in the sensate temperature by ∼1 °C compared to No-Vest case at ambient conditions below 36 °C which can improve thermal comfort and sensation for persons with PA. Moreover, the hybrid vest at activity level of 6 met improved heat losses at the trunk by a factor between 1.88 and 8.57 compared to the no vest case. © 2021 Elsevier Ltd