As climate change accelerates, intense heat waves are no longer rare events but frequent, deadly occurrences. News reports often focus on heat stroke deaths during blistering summers, but the true toll of heat exposure runs far deeper, especially for society’s most vulnerable.

Outdoor and indoor laborers—farmers, construction workers, market vendors—bear the brunt, particularly in tropical regions where heat and humidity are soaring. For many, the burden doesn’t end at work. After exhausting shifts, they return to sweltering homes lacking ventilation, cooling devices, or respite, continuing their exposure.

Prolonged heat doesn’t just cause immediate crises like heat stroke. It silently worsens heart, lung, and kidney conditions, with fatalities often unrecorded as heat-related. Dubbed the “invisible killer,” extreme heat’s widespread impact is frequently underestimated.

The fallout extends beyond health. Studies show rising temperatures correlate with increased anxiety, violence, self-harm, and deteriorating reproductive health. Labor productivity plunges, especially harming informal and gig workers whose livelihoods depend on daily wages.

Since 2023, researchers have partnered with India’s Self Employed Women’s Association (SEWA)—representing over 3.2 million women workers—to document the worsening crisis. Three consecutive summers of extreme heat have devastated SEWA members’ incomes, mental health, food security, and children’s education. Nearly 80% report income loss, 40% face mental health challenges, and many struggle to afford basic cooling options.

SEWA members emphasize the vicious cycle: lost wages heighten stress, disrupt families, and deepen poverty. They are now exploring solutions like parametric heat insurance and community-led adaptations, calling for more inclusive scientific research to shape climate-resilient policies.