Extreme heat disrupts treatment and daily routines for cancer patients

New research published in the journal Environmental Research: Climate found that extreme heat is already influencing how people with cancer manage daily life, access care, and make treatment-related decisions. 

The study, led by researchers from Sylvester Comprehensive Cancer Center, part of the University of Miami Miller School of Medicine, as well as from the Rosenstiel School of Marine, Atmospheric, and Earth Science and the School of Nursing and Health Studies, highlights the need to integrate environmental risk into cancer care planning, from clinical conversations and appointment planning to caregiver guidance and community support. 

Based on in-depth interviews with cancer-affected individuals in South Florida, a region that is warming faster than many parts of the country, the research offers an early view into challenges that health systems elsewhere may soon face as extreme heat becomes a more constant presence globally. 

What we heard was that heat touches nearly every part of people's routines. It affects when people go outside, whether they adhere to medical advice, how connected they feel and how much they spend just to stay safe and comfortable." 

Kilan C. Ashad-Bishop, Ph.D., a Sylvester and Rosenstiel researcher and lead author of the study

Some patients delayed or skipped medical visits to avoid heat exposure. Others reduced physical activity, social interaction or essential errands. For individuals already managing treatment side effects, fatigue or financial strain, heat became another force narrowing their choices. 

Extreme heat refers to significantly hotter periods-and often more humid-than average for a given place and time, according to the U.S. Environmental Protection Agency. As global temperatures continue to rise, longer heat seasons and more frequent extreme heat days are expected. 

And as a particularly strong El Niño approaches, climate experts predict that 2027 could be the planet's warmest year on record.

Despite growing evidence that environmental conditions pose health risks, little research has focused specifically on how extreme heat affects people with cancer. To address that gap, the researchers turned directly to those experiencing it. 

The qualitative study, titled "When It Comes to Heat, I Retreat": Heat Impacts and Adaptation Practices Among People With Cancer," included interviews with 20 adults across 18 ZIP codes in South Florida, one of the nation's most heat-exposed regions. All participants had a history of cancer diagnosis or treatment and described how heat affects their health, access to care, finances and social lives. 

Interviews were conducted in English and Haitian Creole, capturing experiences across communities and highlighting how heat stress can compound existing health and financial challenges.

Participants described adapting in creative ways, such as limiting outdoor activity, planning errands during cooler hours, staying indoors and relying heavily on air conditioning. But those adaptations often came with tradeoffs that affected health, independence and quality of life. 

Rather than triggering sudden crises, the researchers found that heat strain often works incrementally through a series of small compromises that can quietly shape long-term well-being. 

"We saw people making calculations as constant as heat stress in South Florida," Dr. Ashad-Bishop said. "They're weighing comfort against care, safety against necessity. Those decisions add up." 

"This isn't just about weather advisories," said Sophia George, Ph.D., Sylvester researcher, associate professor in the Miller School's Department of Obstetrics, Gynecology and Reproductive Sciences and senior author of the study. "It's about recognizing heat as a health stressor and helping patients plan for it as part of everyday care."