Indoor overheating influences self-reported symptoms and mood-state in older adults during a simulated heatwave: Effects of mid-day cooling centre use

• Published in: Physiology & behavior 2023-11, Vol.271, p.114335-114335, Article 114335
• Main Authors: McGarr, Gregory W., Meade, Robert D., Kenny, Glen P.
• Format: Article
• Language: English
• Subjects: Ageing; behavior; Climate change; cooling; emotions; energy; heat; heat exhaustion; Perception; Personal cooling interventions; physiology; public health; questionnaires; temperature; Thermal comfort; Thermal sensation
• ISSN: 0031-9384; 1873-507X
• DOI: 10.1016/j.physbeh.2023.114335

•We tested thermal and perceptual strain of older adults during indoor overheating.•Indoor overheating increased thermal strain, heat symptoms and mood disturbance.•Cooling centre use reduced heat symptoms and mood disturbance upon return to heat.•Body temperatures rapidly returned to pre-cooling levels upon return to heat.•Individuals may underestimate indoor overheating risk after cooling centre use. Public health agencies recommend that older adults without home air-conditioning visit cooling centres to mitigate physiological strain from high ambient temperatures during heat waves. However, there is little evidence regarding their influence on self-reported environmental symptoms and mood-state after returning to the heat. Forty adults (64–79 years) underwent a daylong laboratory-based indoor overheating simulation (9-hours, heat index: 37 °C) with (cooling, n = 20) or without (control, n = 20) a 2-hour air-conditioning intervention (hours 5–6). Mean skin and core temperature areas under the curve (AUC, hours 0–9) were used to assess cumulative thermal strain. Group differences in total symptom scores and subjective heat illness (68-item environmental symptoms questionnaire) as well as total mood disturbance and energy index (40-item profile of mood states questionnaire) were evaluated at end-heating (adjusted for pre-exposure scores). Cooling reduced mean skin and core temperature AUCs by 4.0 [0.1, 0.8] and 1.6 [0.4, 2.8] °C·hour compared to control (both p  0.999). Total symptom scores and subjective heat illness were 0.58-fold [0.44, 0.77] and 0.56-fold [0.40, 0.78] lower in the cooling compared to control group (both p