Social media: Reading between the lines

Irvine, Calif., Aug. 27, 2026 - As extreme heat becomes more frequent and intense across California, knowing which communities are struggling and what kind of help they need is increasingly important for protecting public health.

A new UC Irvine study suggests that part of the answer may be hiding in everyday conversations on social media.

Researchers analyzed 24,598 heat-related posts on Twitter, now X, from across California between 2016 and 2022. They found that where people live, how they get around and the resources available to them were associated with meaningful differences in how they talked about extreme heat - including whether they described its effects on their lives or discussed ways of coping with it.

The findings, published in Environmental Research Communications, point to social media as a potential complementary tool for understanding how communities experience extreme heat and for developing more targeted public health interventions.

The study was conducted by Nicolas Rodriguez Garcia and senior author Suellen Hopfer of the Joe C. Wen School of Population & Public Health; Veronica J. Berrocal of the Department of Statistics; and Chen Li of the Department of Computer Science - the latter two in the Donald Bren School of Information & Computer Sciences.

"Social media gives us another window into how people are experiencing heat in their daily lives," says Hopfer, associate professor of health, society and behavior. "Understanding those experiences can help us think more strategically about who heat-safety messages are reaching, where gaps remain and how communication can better support communities that are especially vulnerable."

Looking beyond the temperature

Extreme heat is a growing public health threat, and housing, income and occupation are known predictors of heat vulnerability. Rather than looking only at temperatures or heat-related illnesses, the UC Irvine team examined how people described heat's impact on their daily lives and the ways they coped with it. This revealed that individuals living in RVs, vans or boats - termed "sensitive housing" - may benefit from targeted public health interventions designed to reduce indoor heat exposure.

The researchers categorized posts according to whether people were discussing coping strategies - such as staying hydrated, using air conditioning, going to a pool or changing when they exercised - or life impacts, including health effects, disrupted work, canceled activities, concerns about pets or plants, changes in household expenses and other consequences of high temperatures.

They then compared those patterns with county-level indicators related to income, housing, transportation and tree canopy. In general, housing was correlated with posts about coping, while being an active commuter predicted life-impact posts.

The researchers also used a large language model to help group thousands of social media posts based on how people talked about heat. They checked the model's results against a set of posts that the team had manually sorted, learning that the model's accuracy ranged from 74 percent to 90 percent across the categories of heat impacts, coping strategies and "other."

Some of the clearest differences emerged around housing.

Counties with high levels of RV/van/boat households were 15 percent less likely to post positive heat tweets than counties with low levels and had 22 percent lower odds to posts about coping strategies. That finding is especially important because such homes can have poor insulation and become dangerously hot during extreme temperatures.

The researchers say the pattern points to an opportunity for more targeted communication about indoor heat safety, particularly for people living in housing where maintaining a safe temperature may be difficult.

Transportation patterns revealed another vulnerability.

Counties with greater percentages of people who walk, bike or use public transportation to commute showed substantially greater odds of negative heat-related posts and those describing the effects of heat on daily life. The researchers note that active commuters can experience direct heat exposure while traveling, making transportation infrastructure an important part of protecting communities from rising temperatures.

The study also identified disparities in counties with larger Hispanic populations. Those counties showed a slightly greater likelihood of posts describing heat's impacts on daily life and a lower likelihood of posts on coping strategies. The researchers caution that social media patterns should not be treated as direct measures of population-level vulnerability but say the results highlight an opportunity for more targeted heat awareness and intervention efforts.

Turning online conversations into public health insights

The researchers envision social media not as a replacement for established public health surveillance but as another source of information that could help officials understand how extreme heat is affecting people as events unfold.

The study found that heat-related posting increased as average monthly temperatures rose. Because online conversations can capture immediate experiences - from struggling with an overheated home to changing a commute or canceling an activity - they may reveal aspects of heat exposure that are difficult to capture through conventional datasets alone.

Combining those signals with measures of housing, transportation and socioeconomic conditions could eventually help public health agencies identify where particular kinds of heat communication are most needed.

For example, communities with substantial sensitive housing might benefit from messaging focused on keeping indoor spaces safe, while areas with many active commuters could benefit from heat-conscious transportation planning and interventions that reduce exposure while walking, cycling or waiting for public transit.

Ultimately, the researchers say, blending social media monitoring with automated language analysis could offer another way to identify communities that would benefit from targeted heat warnings, practical guidance and longer-term mitigation strategies.

As California prepares for a future of increasingly frequent and severe heat events, those insights could help public health officials move beyond one-size-fits-all warnings and toward communication designed around how people experience and cope with extreme heat.

About the University of California, Irvine: Founded in 1965, UC Irvine is a member of the prestigious Association of American Universities and is ranked among the nation's top 10 public universities by U.S. News & World Report. The campus has produced five Nobel laureates and is known for its academic achievement, premier research, innovation and anteater mascot. Led by Chancellor Howard Gillman, UC Irvine has more than 36,000 students and offers 224 degree programs. It's located in one of the world's safest and most economically vibrant communities and is Orange County's second-largest employer, contributing $7 billion annually to the local economy and $8 billion statewide. For more on UC Irvine, visit www.uci.edu.