Reddit discussions could help improve public health messaging on heat

Two years ago, Robbie M. Parks, an environmental health scientist at Columbia University Mailman School of Public Health, and Nathaniel Matthews-Trigg, director of climate and disaster resilience at Americares, founded an online community on Reddit, r/heat_prep, where members share information and advice about coping with extreme temperatures. A new article in the Journal of Climate Change and Health details the growing community, its concerns, and its potential to model how to communicate about climate change-related extreme heat and other public health concerns.

Parks, Matthews-Trigg, and co-authors analyzed the most popular posts from r/heat_prep, which today has more than 20,000 members, and administered a survey. They found that engagement peaked during the Northern Hemisphere warm season, with posts centered on practical advice, personal experiences, and improvised cooling strategies. Most respondents reported frequent heat discomfort and associated physical and mental health effects, and preferred Reddit for heat-related information over traditional channels. Community discussions highlighted low-cost adaptations, peer-driven innovation, and emotional support through humor and collective sense-making.

"As climate change intensifies extreme heat, lived experiences of hazardous conditions are increasingly documented in large online communities, which form global spaces where people discuss, experiment, and crowd-source strategies for responding to heat-related challenges," the authors write.

Across content analyses and survey responses, a recurring pattern emerged: a disconnect between official heat-health guidance and the advice some people seek as temperatures rise.

Public health messaging around heat is often "technical, generalized, or conditional, which can limit its perceived usefulness and drive people toward online communities," according to the researchers. Institutions like the U.S. Centers for Disease Control and Prevention (CDC) tend to emphasize a standard set of personal actions, like staying in air-conditioned spaces, while offering limited guidance for people without affordable cooling, living in poorly insulated housing, or facing disabilities or health-related constraints.

To fill this gap, the authors argue that some people seek strategies better suited to their lived realities and material constraints. On r/heat_prep, users also share practical "hacks" (for example, "How to try and stay cool without AC"), validate concerns, and collectively evaluate solutions. One widely circulated thread compared low-cost shading materials for sun-exposed windows, demonstrating how films, reflective blankets, and cardboard shields could reduce indoor heat gain. Other posts recommended placing frozen water bottles in front of box fans to enhance cooling, or lining curtains with foil to reflect incoming solar radiation.

"Unlike largely unidirectional official heat communication, Reddit enables dialogue, peer feedback, and iterative problem-solving, bridging expert guidance and lived experiences," the authors write.

While misinformation can spread on Reddit, active moderation can prevent it. The authors suggest that public health agencies team up with moderators "to seed accurate, accessible information directly into these spaces" through pinned posts and expert Q&As (e.g., via Ask Me Anything sessions). Additionally, communities like r/heat_prep can serve as an informal early warning system, revealing confusion, unmet needs, and practical constraints that may be missed by formal health communication.

The article's first author is Gabriela Imbert, the Graduate School of Arts and Sciences, Columbia University. Robbie M. Parks is the senior author. Additional authors include Kim R. van Daalen, University of Cambridge; and Nathaniel Matthews-Trigg.