On World Health Day 2026, the World Health Organisation (WHO) South-East Asia Region called for urgent, science-led action to address complex health risks exacerbated by climate change and evolving disease patterns. Dr. Catharina Boehme, Officer-in-Charge at WHO, highlighted the importance of a One Health approach, which integrates human, animal, and environmental health. The theme 'Together for Health. Stand with Science' emphasizes the necessity of basing health policies on scientific evidence to protect lives. Initiatives like the South Asia Hub of the Global Heat Health Information Network (GHHIN) aim to translate scientific data into actionable early warnings against extreme heat. Countries such as Bangladesh, Sri Lanka, and India are showcasing effective strategies in health surveillance and response. WHO stressed the need for governments and institutions to invest in science-based policies, urging scientists to share actionable evidence and communities to adopt protective behaviors. As health risks become more interconnected, collaboration is vital for building a healthier, resilient future.