Investigating the Effect of Single-session Sauna Use on Body Temperature

Inclusion Criteria: * Male or pre-menopausal female volunteers aged 18-45. * Able to understand the nature of the study and able to provide written informed consent prior to conduct of any study procedures. * Able to communicate in English with study personnel. * Able to lay supine for 2 hours in a sauna. * BMI \<=30 * Waist size of \<=40 inches for men or \<=35 inches for women * Have a smartphone * If female, and sexually active with men, must agree to use non-hormonal birth control (e.g., barrier methods, partner with vasectomy, tubes tied, copper IUD) * Must have negative pregnancy test day of sauna session Exclusion Criteria: * Any history of or current mental health condition * Any current medical condition requiring medical treatment * Any history or current substance misuse/abuse * Regular use of any nicotine products, including cigarettes, e-cigarettes, chewing tobacco, or other forms of nicotine * Unable to refrain from psychoactive dietary or herbal products, including marijuana, in the 2 weeks prior to study participation * Breastfeeding or pregnant women, women intending to become pregnant within 6 months of the screening visit * Sexually active women of child bearing potential who are not using a medically accepted physical means of contraception (defined as non-hormone-based implant, condom, diaphragm, status-post tubal ligation, or partner with vasectomy) * Current use of hormone-based birth control, such as IUD or oral contraceptive * Needing to use of any medication that might impact thermoregulatory capacity within 5 days of the sauna session, including: stimulants, diuretics, barbiturates, beta-blockers, antipsychotic agents, anti-cholinergic agents or chronic use of antihistamines, aspirin (other than low-dose aspirin for prophylactic purposes), non-steroidal anti-inflammatory drugs (NSAIDs), systemic corticosteroids, cytokine antagonists * Current antidepressant medications (all classes) or use within the past 30 days The following medications in these timeframes: * Antibiotics (past 60 days) * Pain medication (opioids) due to procedure, e.g., dental procedure (past 30 days) * Emergency contraception pill (past 60 days) * Benzodiazepines, e.g., procedure (past 30 days) * Use of any other medication that in the judgment of the PI would increase risk of study participation or introduce excessive variance into physiological or behavioral responses to WBH * Known hypersensitivity to infrared heat exposure * Unwilling to refrain from sauna use outside of study procedures for one week before and one week after sauna session