2021年6月，一場破紀錄的熱穹籠罩加拿大溫哥華，氣溫飆升超過攝氏39度，夜間也無法降溫。急診醫師Jeff Yoo面對大量中暑患者湧入，醫院冰塊耗盡、病床不足，走廊擠滿擔架。他搶救了一名昏倒在人行道上的中年男子，該男子嚴重脫水、腎臟衰竭，最終靠冰敷和膀胱導管輸入冷液才穩定下來。Yoo注意到，許多熱穹期間送醫的患者都有一個共同特徵：他們患有思覺失調症。
研究顯示，思覺失調症患者在極端高溫中的死亡風險是其他慢性病的三倍，遠超心臟病、糖尿病和氣喘等疾病。其原因是多層次的：患者的多巴胺調節異常影響體溫控制，交感與副交感神經系統失衡導致心血管功能受損，而抗精神病藥物的抗膽鹼作用會抑制排汗，進一步削弱散熱能力。此外，高溫本身會加劇思覺失調症狀，使患者陷入恐懼與戰鬥逃跑反應的惡性循環。患者往往缺乏對自身健康狀況的認知，可能不知道補水或降溫，甚至在酷暑中穿上多層衣物。
除了生理因素，社會性風險同樣致命。許多思覺失調症患者因偏執症狀而迴避媒體，不知道熱浪即將來襲；社會污名使他們不敢前往公共降溫中心；貧困導致住所缺乏空調——98%的熱穹死亡發生在室內。不列顛哥倫比亞省此後投入1.48億加元增聘急救人員、將思覺失調症列為高溫高風險首位、建立照護者聯繫機制、推出免費冷氣機計畫並更新緊急警報系統。波特蘭的經驗也表明，在降溫中心部署行為健康工作者能有效幫助猶豫不前的患者，甚至挽救生命。隨著全球暖化加劇，針對這一最脆弱群體的系統性保護措施刻不容緩。
During the unprecedented 2021 heat dome that engulfed Vancouver, British Columbia, temperatures soared past 102°F for over a week, overwhelming emergency rooms with heat-related patients. ER doctor Jeff Yoo at St. Paul's Hospital witnessed the crisis firsthand as 911 calls doubled, ice supplies ran out, and hallways filled with stretcher-bound patients. Among those he treated was an unconscious man found on the sidewalk suffering severe heatstroke and kidney failure, who had to be physically restrained and cooled with ice packs and a bladder catheter. Yoo noticed a striking pattern: many of the heat dome's victims exhibited symptoms of schizophrenia, a condition affecting roughly one percent of the global population.
Subsequent research revealed that schizophrenia carries a threefold increase in the odds of heat-related death—far exceeding every other chronic condition studied, including heart disease, diabetes, and dementia. The vulnerability stems from compounding biological factors: impaired dopamine regulation disrupts thermoregulation, an imbalance between the sympathetic and parasympathetic nervous systems compromises cardiovascular function, and antipsychotic medications suppress sweating through anticholinergic effects. Heat itself can also trigger worsening psychiatric symptoms, creating a vicious feedback loop of anxiety, fear, and physiological stress. Beyond these internal factors, many patients lack insight into their deteriorating condition and may fail to hydrate or cool themselves, sometimes even adding layers of clothing in extreme heat.
Social and structural barriers compound the physiological risks dramatically. Many people with schizophrenia avoid news media due to paranoia, leaving them unaware of approaching heat waves. Stigma discourages them from visiting public cooling centers, and poverty means their homes often lack air conditioning—98 percent of heat dome deaths occurred indoors. Since 2021, British Columbia has invested $148 million in emergency services, prioritized schizophrenia in heat-risk guidelines, launched a free air conditioner program serving 40,000 people, and updated cell phone alert systems for extreme heat. Portland's experience demonstrated that stationing behavioral health workers at cooling centers can effectively reach hesitant individuals and save lives. As climate change drives increasingly frequent extreme heat events, experts emphasize that addressing stigma alongside practical interventions like cooling access and pharmacist-led medication counseling is essential to protecting this uniquely vulnerable population.