Digital CBT-I with or without sauna-blanket body heating for insomnia

You may qualify if

• 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)

You can't join if

• 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 insomnia, require priority treatment, or be exacerbated by time in bed restriction
• Medical condition that may better explain insomnia, require priority treatment, or be exacerbated by time in bed restriction
• Lifetime diagnosis of a bipolar disorder, psychosis, or other psychotic disorder
• Current (past 3 months) major depressive disorder
• Current (past 12 months) suicidality, alcohol use disorder, other substance use disorder (except mild cannabis use disorder), panic disorder, agoraphobia, social anxiety disorder, obsessive-compulsive disorder, attention-deficit/hyperactivity disorder, post-traumatic stress disorder, and eating disorders
• If using medications for mental health treatment (e.g., antidepressant medication) must have been on a stable dose for prior 8 weeks
• Currently receiving cognitive behavioral therapy for insomnia (CBT-I)