Background Climate change is increasing the frequency and severity of heatwaves across South Asia, with disproportionate impacts on vulnerable populations. Pregnant and lactating women face heightened health risks due to physiological changes, gendered social responsibilities, and constrained access to adaptive resources. Despite this, women’s lived experiences and adaptation practices during pregnancy remain understudied and largely absent from institutional climate responses. This knowledge gap hampers the development of effective, gender-sensitive adaptation policies. Methods This qualitative study, embedded within the Heat in Pregnancy (HiP)-India project, will be conducted in three climatically vulnerable sites: Gurugram (Haryana), Bilaspur (Chhattisgarh), and Puducherry. Guided by a socio-ecological framework, we will conduct in-depth interviews with pregnant and lactating women, focus group discussions with caregivers, and key informant interviews with health workers and local stakeholders, alongside non-participant observations. Interviews will take place during and shortly after the heat season to capture both real-time and reflective experiences. Using purposive sampling, we will recruit 20–25 women per site, along with caregivers and stakeholders, primarily from the HiP-India cohort who have consented to follow-up. Data will be thematically analysed using NVivo, with reporting guided by COREQ standards. Anticipated Results The study will generate contextualised insights into women’s heat-adaptation practices during pregnancy and lactation across diverse agro-climatic zones, document traditional and emerging coping strategies, and identify structural, social, and institutional barriers shaping adaptation capacity. Conclusion By centering women’s lived experiences, this research will inform the design of culturally appropriate, gender-responsive heat adaptation interventions suitable for low-resource settings. Findings will support both practical community-based solutions and evidence-based advocacy for more inclusive climate adaptation policies at local and national levels.