Human Adaptation to Daytime Heat and Associated Heat‐Related Symptoms Among Women
Sagheer Hussain, Nazish Chaudhary, Shoukat Ali Mahar, Abdul Wahid Zehri, Shakeel PatrusABSTRACT
Objectives
To assess associations of daytime temperature with reported behavioral heat adaptation and heat‐related symptoms, and to assess whether the temperature–symptom association remained after accounting for behavioral adaptation.
Methods
A community‐based cross‐sectional study was conducted among 480 women aged 18–49 years from 40 sampling clusters in five districts of Sindh, Pakistan, from April to July 2026. Objective daytime mean temperature was the primary exposure. Behavioral adaptation and heat‐related symptoms were assessed using a structured questionnaire. Multivariable regression models adjusted for age, education, household size, and income, with standard errors clustered at the sampling cluster level. Linear and quadratic temperature specifications were examined.
Results
Mean daytime temperature was 41.85°C (SD, 1.78; range, 38.2°C–45.9°C). Behavioral adaptation was reported by 58.5% of participants, and at least one heat‐related symptom by 95.8%. Higher temperature was associated with greater odds of behavioral adaptation (OR, 2.28; 95% CI, 1.92–2.70; p < 0.001). The quadratic temperature term indicated attenuation at higher temperatures (OR, 0.91; 95% CI, 0.83–0.99; p = 0.037), with a turning point estimated at 46.2°C, above the observed maximum. Even after controlling for behavioral adaptation, temperature was still linked to heat‐related symptoms (OR, 1.51; 95% CI, 1.12–2.03; p = 0.007).
Conclusions
Higher daytime temperature was associated with higher reported behavioral adaptation, with a reduction toward the upper end of the observed range. Reported behavioral adaptation remained associated with temperature, while heat‐related symptoms also remained associated with higher tempratures. The cross‐sectional study does not establish a mediating effect.