Abstract
<title>Abstract</title> <p>Perceived thermal stress may offer greater physiological relevance than air temperature; however, its effects on brain-related outcomes remain unclear. We examined persistent effects of lifetime human-perceived thermal stress on lifestyle, brain, and behavior in 5,851 healthy young adults. Longer durations of uncomfortable thermal stress were associated with weaker sour and spicy preferences, higher fish and poultry intake, greater sleep-related daytime dysfunction, smaller cerebral and larger cerebellar volumes, lower white-matter integrity, greater harm avoidance and novelty seeking, lower reward dependence, and reduced psychological well-being. Strong thermal stress was further associated with two additional outcomes. Several cumulative effects showed sensitive periods, with congruent or incongruent effect directions. Although thermal stress affected brain and behavior via direct effects, some behavioral effects were partially mediated by lifestyle alterations. These findings indicate that perceived thermal stress has persistent effects on brain-related outcomes in extraordinarily healthy individuals, supporting its broader use for evaluating thermal-related brain alterations.</p>