Review: The future of nature-based recreation in warming tropical cities. Image Credit: taka1022 / Shutterstock A recent review article published in the journal npj Urban Sustainability reviewed evidence on outdoor recreation and humid heat stress in tropical cities. Cities worldwide are shifting toward urban greening to harness nature's benefits. Nature-based recreation in cities can promote physical and mental health, enhance community resilience, and strengthen social cohesion. However, outdoor recreation in tropical cities often means exposure to hot, humid conditions that are thermally uncomfortable, which, in extreme cases, can even be unsafe for humans. Public health recommendations may be perceived as conflicting because they encourage outdoor recreation while also warning against heat exposure. Therefore, it is crucial to determine the appropriate outdoor exposure levels in hot environments to differentiate between harmful heat stress and safe exposure. In the present review, researchers summarized evidence on outdoor recreation and humid heat stress in tropical cities and outlined adaptation strategies. Rise in urban heat in tropical regions Extreme temperatures have increased in intensity and frequency worldwide due to elevated greenhouse gas emissions, with urban warming further amplifying these trends. Increased heat from air conditioning use or transportation, construction materials that retain more heat, surface sealing that reduces evapotranspiration and infiltration, and altered surface geometry all drive urban warming. High temperature and humidity in tropical cities can lead to adverse health outcomes. While the contribution of humidity to heat-related health outcomes is debatable, there is consensus that increased heat stress may deteriorate population health. Many tropical cities are projected to undergo rapid urbanization over the coming decades, with climate change expected to worsen heat hazards in humid, hot regions. Tropical urban populations face heat health vulnerability The increase in heat stress means tropical urban populations are often exposed to adverse climates. While the physiological limits