FLOAT for Healthcare PTSS

Inclusion Criteria: 1. Work-related post-traumatic stress dysfunction as measured by either of the following inclusion pathways: (A) PTSS Pathway: PCL-5 greater than or equal to 20, OR meets criteria for full or partial PTSD on the MINI International Neuropsychiatric Interview 7 (DSM-V) (Criteria A + at least 2 B-E Criteria) OR (B) Functionally Anchored Pathway: evidence of work-related trauma exposure on the MINI International Neuropsychiatric Interview 7 (DSM-V) (Criterion A) or Life Events Checklist-5, and at least one of the following: Moral Injury and Distress Scale greater than or equal to 27, Sheehan Disability Scale greater than or equal to 5 on at least 1 of the 3 subscales, high or very high level of perceived stress (measured by PhenX Perceived Stress Scale greater than or equal to 16). 2. First responder or other emergency medical personnel 3. Ability to read, speak and understand English 4. Capable of providing consent Exclusion Criteria: 1. History of neurological conditions 2. Skin conditions or open wounds 3. DSM-5 diagnosis of psychotic spectrum disorders, obsessive-compulsive disorder, bipolar disorder, severe substance use disorder, or eating disorder 4. Inability to lay comfortably in a shallow pool of water 5. Failure to adhere to "pre-float checklist" 6. Breathalyzer test positive for alcohol or a drug-positive urine test 7. Unwillingness to provide consent or complete major aspects of protocol 8. MRI contraindications 9. Unstable medical diagnoses 10. Pregnancy 11. Evidence of inability to comply with study procedures based on experimenter judgement 12. Change in the dose or prescription of a medication within the 6 weeks before enrolling in the study that could affect brain functioning (e.g., anxiolytics, antipsychotics, antidepressants, benzodiazepines, or mood stabilizers)