Optimizing an Integrated Mind and Body Treatment for Insomnia: The SLEEPS Study 2

Inclusion Criteria: * 18 years or older * English-speaking * Willing to use birth control if assigned female sex at birth * Willing to receive study text messages during participation * Location to plug sauna blanket into regular wall outlet * Ability to lie in sauna blanket for 15 minutes * Ability to fit in the sauna blanket * Daily access to the internet via computer, smartphone, or tablet * Elevated insomnia symptoms as indexed by a score of 11 or greater on the Insomnia Severity Index (ISI) at two screening timepoints * Primary insomnia disorder (characterized by difficulty initiating sleep) as indexed by a positive diagnosis on the Structured Clinical Interview for DSM-5 Sleep Disorders (SCISD) Exclusion Criteria: * Night shift or swing shift worker * Current or planned routine body heating practices (e.g., saunas, hot tubs, long baths) within 4 hours before bed that are 10 minutes or more in duration (≥2x per week) * Pregnant or plans to become pregnant during the participation period * Traveling internationally between screening assessment and anticipated post-intervention assessment, or during anticipated post-follow-up assessment period (\~1 week) * Other diagnosed sleep disorders or suspected sleep disorders * Medical conditions that might increase the risk of passive body heating using an infrared sauna blanket * Medication use that might increase the risk of passive body heating using an infrared sauna blanket * Mental health disorder that may better explain i…