Green spaces are not the answer to overheated cities by themselves. Careful urban planning needs to consider their strategic placement. When it comes to climate adaptation options, one of the key messages coming from the Intergovernmental Panel on Climate Change is for cities to integrate their grey and green spaces. While modern cities have largely moved on from traditional practices, our forebears may have understood more than we realise about living with nature. Increasingly, researchers specialising in how cities can cope with climate change are encouraging us to regain local knowledge of nature. City developments often don’t consider orientation, water, wind flows, and light. In face of urban warming, air conditioning remains almost the standard response in more developed nations, whatever the weather. Air-conditioners can significantly reduce heat-health risk, but the cost of electricity prices many poor people out. Air-conditioners that emit heat to outdoor environments also increase heat stress for people outdoors. All while climate change is increasing the magnitude, frequency, and duration of extreme high temperatures. Highly populated cities in warm and humid climates are particularly at risk. Urban areas are generally several degrees warmer than rural surroundings due to the replacement of natural surfaces with hard pavements and buildings, a phenomenon well known as the urban heat island effect. The loss of natural areas in the process of urbanisation reduces the mechanism of evaporative cooling and shading from tree canopy. Development that blocks natural channels of cities, such as valleys, riversides, and coastal fronts, also reduces natural ventilation. Local-level governments that determine land use and development can play a crucial role in heat-risk reduction in several ways. For example, modifying planning regulations, land zoning and building codes for improving ventilation and green spaces can lower the urban heat island effect. This adjustment of land use can have huge impacts on the health and well-being of citizens, as well as improving social equality in heat adaptation. Enhancing ventilation of cities and increasing tree coverage in hotter and less affluent areas might help reduce the need of air conditioners, and help mitigate heat-related health risks for the most vulnerable. The city of Stuttgart, Germany was famously a pioneer of ‘climatological planning’. A valley city, having suffered from poor access to light and fresh air for many years, Stuttgart was astonishingly forward-thinking in appointing climatologists to participate in urban planning in 1938. Building upon years of research, the city determined that cleansing winds were blocked from sweeping down forested hills by inappropriate building development. They adjusted the planning controls to specify a greater open-space to development ratio on hillside parcels of land. Critical geographical features that influence air flow, such as mountain forests, rivers, valleys and other green spaces, are designated ventilation zones in the urban plan. Taipei is a subtropical city nestled in a basin. Some studies suggest a sea-land circulation of air through the city. During summer days, the breeze from the sea and forested mountains follows the major river valleys of the Danshui, Keelung, and Dahan Rivers through the city, cooling as they pass. However modern urban development has ignored this natural mechanism. Many mountain valleys are developed into transportation corridors and intensive development occupies the waterfront areas. This likely blocks the breezes from penetrating the city. Indeed, with more intense urbanisation compared with other cities in Taiwan, Taipei has shown a faster and more obvious warming trend in the past few decades. Yet, when the time comes for urban regeneration, there is still a chance for planners to integrate climatological knowledge. They could identify ventilation zones with critical natural geographical features, and systematically allocate open spaces to allow prevailing winds to harness cooling services. Green spaces are well known to regulate the micro-climate of a city, lowering the temperature of their surroundings. However, this cooling effect has its limitations; beyond 100m they can barely be perceived. Development geometry around green spaces determines how far cool air can penetrate. If there are no adjacent heat sources, no physical barriers blocking air flow, and good winds, cool air might flow further. Hence, simply increasing ‘green coverage’ without considering relative location of green spaces cannot effectively reduce the problem of urban warming. Understanding this cooling mechanism is particularly critical for cities like Taipei, which has been densely built.