Global heat wave days jump to 19.3 a year: Women in low- and middle-income nations at high risk

Hyderabad: Between 2007 and 2023, the global average number of heat wave days increased to 19.3 per year, up from 12 days in the preceding decade.

As extreme heat becomes more frequent and intense, new research shows that low- and middle-income countries (LMICs) remain poorly equipped to manage the health impacts of heat, particularly for women.

A review conducted by researchers from The George Institute for Global Health and Imperial College London has found that most heat adaptation efforts in LMICs continue to focus on infrastructure and climate mitigation, with limited attention to health outcomes and significant gaps in gender inclusion.

Extreme heat a growing public health threat

Heat waves are now among the deadliest climate-related hazards, with prolonged exposure linked to dehydration, cardiovascular strain, sleep disruption and worsening of existing medical conditions.

The study notes that LMICs face a disproportionate burden due to inadequate housing, limited healthcare access and high levels of outdoor and informal labour.

Women, especially those who are pregnant, face heightened risks. Heat exposure during pregnancy has been associated with complications such as preterm birth.

Social factors further increase vulnerability, as many women work in settings without access to shade, rest breaks or clean drinking water.

Limited evidence on what works

The researchers reviewed published studies on community-level heat adaptation interventions in LMICs between 2013 and 2024 to assess their impact on health.

Only five studies met the inclusion criteria, highlighting the lack of robust evidence to guide policy decisions.

The eligible studies were conducted in India, Pakistan, Nicaragua, Burkina Faso and El Salvador. Interventions examined included cool roofing solutions, workplace policies such as water-rest-shade breaks, and community education programmes aimed at improving awareness of heat risks.

Health outcomes assessed ranged from physiological indicators like heart rate and sleep quality to changes in behaviour and attitudes related to heat exposure.

Heat adaptation is still treated as a climate issue

One of the key findings of the review is that heat adaptation continues to be addressed mainly as an infrastructure or climate challenge, rather than a public health concern.

As a result, policymakers lack clear evidence on which interventions should be prioritised or scaled to protect population health.

The study argues that without integrating heat-related health risks into healthcare systems, particularly primary and maternal care, LMICs will struggle to respond effectively as heat extremes intensify.

Gender is largely missing from research and policy

The researchers also assessed how gender was addressed in the reviewed studies using a World Health Organisation–recommended framework that classifies interventions from ‘gender-blind’ to ‘gender-transformative.’

Most of the studies were found to be gender-blind, meaning they did not account for differences in exposure, vulnerability, or health outcomes between men and women.

“Our review shows that evidence on heat-health interventions in LMICs remains extremely limited, and gender is almost entirely absent in existing evaluations,” said Karthika Kumar, Research Fellow at George Institute Services.

“As heat extremes intensify, we need adaptation strategies that reflect women’s lived realities and measure real health outcomes. Strengthening this evidence base is essential to protect populations most affected.”

Why women’s inclusion matters

According to the researchers, women play a central role in community-based interventions, from household decision-making to health education and caregiving. Excluding women from the design and evaluation of heat adaptation measures weakens their effectiveness and limits long-term sustainability.

Highlighting the broader implications, Dr Jane Hirst, Program Director, Women’s Health, The George Institute for Global Health, UK, said, “This study highlights the urgent need to design climate adaptation interventions that consider the specific needs of everyone, especially women and girls.”

Recommendations for future heat adaptation

The study calls for a shift towards health-centred and gender-aware heat adaptation strategies. Recommended measures include expanding structural solutions such as cool roofing and shaded public spaces, integrating heat-related health risks into primary and maternal healthcare services, and identifying high-risk populations to ensure equitable access to heat-relief interventions.

The researchers also emphasise the need for future studies to collect sex-disaggregated data and conduct rigorous gender analysis to inform inclusive policy development.

Preparing for a hotter future

With extreme heat events expected to worsen over the coming decade, the authors warn that failing to strengthen the evidence base could leave millions unprotected.

They conclude that addressing heat as a health emergency rather than solely a climate issue is essential for safeguarding vulnerable populations in LMICs.