Background: Vasomotor symptoms (VMS), or hot flashes, are a common side effect of androgen deprivation therapy (ADT) for prostate cancer (PCa). VMS negatively impact sleep, fatigue, and quality of life (QOL) in PCa survivors. There are few nonpharmacological treatments for VMS. The Embr Wave is a wearable thermal device that applies cooling to thermoreceptors on the inside of the wrist and has been associated with patient reported decreases in hot flash interference in women. We performed a single-arm feasibility study evaluating the Embr Wave for management of VMS in PCa survivors. Methods: 57 PCa survivors reporting bothersome hot flashes were enrolled and instructed to use the device as needed for VMS during the 4-week study. The primary outcome was device usage recorded by the device (minutes and sessions). Additional outcomes included the change in patient reported Hot Flash Related Daily Interference Scale (HFRDIS, range 0-10) and Patient Reported Outcomes Measurement Information System Sleep Disturbance 4a (PROMIS SD, range 0-100) and Sleep Related Impairment 8a (PROMIS SRI, range 0-100). Study procedures were conducted remotely using a virtual clinical trial management platform. Results: The study was conducted from May to Dec 2021 in the US. 44 men completed the study; 39 had retrievable usage data. Median age was 66 (range 57-78) years and median 3 (1-23) years since PCa diagnosis. The most common hormonal treatments were leuprolide (n=22), abiraterone (n=13), and enzalutamide (n=6). Baseline scores indicated moderate hot flash interference and mild sleep disturbance (Table). Mean±SD (median) usage of the Embr device was 3.2±2.5 (2.3) hours and 7.6±3.6 (7.5) sessions per day. 26 (67%) participants reported using the device 7 days/nights each week. Improvements were observed in HFRDIS, PROMIS SD, and PROMIS SRI scores (Table). There were also improvements in subjective ratings of hot flash frequency, duration, interference with daily life/sleep, bothersomeness and control (all p<0.01). The majority (69%) of participants reported that the device was effective at helping them manage hot flashes. No adverse events were reported. Conclusions: Results of this study support the feasibility of use of the thermal device for management of bothersome hot flashes in PCa survivors. Future randomized controlled studies are warranted to evaluate patient reported outcomes related to frequency and severity of VMS, sleep quality, fatigue, and overall QOL, in addition to defining the potential utility of the Embr thermal device in PCa survivors experiencing VMS. Clinical trial information: NCT04892914.