Introduction
MDD, cancer, WBH, dementia
HEAT, CANCER, BLIND
Whether in saunas, sweat lodges, or baths, heat has been used since time immemorial for emotional and physical healing. Recent scientific studies support the wisdom of these ancient practices. For example, repeated sauna use has been associated with long-term protection from cardiovascular and all-cause mortality, as well as dementia [These findings highlight the potential value of identifying mechanisms that account for these hyperthermia-induced mental health benefits. Multiple lines of evidence point to the immune system as an attractive candidate in this regard [The effects of WBH on the immune system when applied clinically appear to vary by the intensity of heat delivered. High-intensity WBH (e.g., to core body temperature between 41 °C and 42 °C), such as is typically used as an adjunct treatment in cancer, reliably induces a time-limited increase in plasma concentrations of most proinflammatory cytokines [To explore this question, and to evaluate whether acute and long-term immune responses to WBH are associated with the procedure’s antidepressant effects, we utilized data from a double blind, randomized, sham-controlled trial to examine the impact of a single treatment with mild-intensity WBH on levels of circulating pro- and anti-inflammatory cytokines in participants with MDD immediately after, and at 1 and 4 weeks after, the intervention. Given that participants who received WBH in this study showed a rapid and sustained antidepressant response when compared to sham treatment [