From the Santa Cruz Shoreline to the NBA: Patrick Spencer Backs Cold Plunge Startup Targeting Mental Health and Peak Performance
By John Tran
For longtime Santa Cruz residents, cold ocean plunges aren’t a trend—they’re tradition. A bracing swim in the Pacific has long been embraced for its energizing, restorative effects. Now, a startup is working to bring the experience inland—with data, hardware, and clinical rigor.
Chillshark, a wellness technology startup founded by Keegan O’Connor, is building what it calls the first personalized cold immersion system—complete with real-time biometrics, integrated software, and medically informed protocols.
O’Connor, who turned to cold immersion during his recovery from PTSD, was struck by the absence of standard guidance. “There was no answer to how long, how cold, or how often,” he said. “Just a lot of guessing.” Chillshark is now attempting to fill that void with a system designed for both elite athletes and everyday users seeking mental clarity, recovery, and stress relief.
The system cools water from 70 to 45 degrees Fahrenheit in under two hours. the unit includes UV sanitation, filtration, programmable presets, and integrations with wearable IoT devices. These sensors allow users to track physiological data—like inflammation, heart rate variability, and sleep quality—adjusting cold exposure accordingly.
But the startup’s ambition goes beyond hardware. It’s working with a clinical advisory board and institutions such as the Grey Team to design the first evidence-based cold immersion protocols tailored to individual health baselines. Early pilot results, according to the company, show reductions in systemic inflammation and measurable improvement in PTSD-related symptoms.
Patrick Spencer, who began his pro career with the Santa Cruz Warriors and played a key role in the 2024–2025 Golden State Warriors’ playoff run, recently joined as an angel investor. Spencer is one of several high-performance athletes turning to cold immersion as a core component of recovery.
“Chillshark has fit seamlessly into my recovery routine as a professional athlete - allowing me to perform at the highest level both at home and on the road. Additionally, the team mission hits close to home as our Spencer Brothers Foundation aims to impact current and veteran military members & their families as they navigate their battle against PTSD.”
Joining Spencer on the cap table is Mike Allard, an angel investor with a background in health tech and a longtime believer in science-based wellness.
O’Connor said the startup is intentionally bridging the gap between wellness trends and clinical standards. “A lot of people have felt the benefits of cold therapy intuitively, but if we want this to be taken seriously in medical and performance settings, it has to be measurable,” he said.
Now in the midst of a fundraising round, the company is scaling its platform and expanding manufacturing. Its broader ambition: to standardize cold immersion therapy in a way that meets the needs of pro teams, military recovery units, and individual users alike.
From NBA locker rooms to coastal enclaves like Santa Cruz, Chillshark is betting that the future of recovery isn’t about guesswork—it’s about personalization, precision, and cold backed by science.
