This chapter of the New York City Panel on Climate Change 4 (NPCC4) report focuses on climate health risks, vulnerabilities, and resilience strategies in New York City's unique urban context. It updates evidence since the last health assessment in 2015 and addresses emerging climate health risks and vulnerabilities specific to NYC. The chapter emphasizes climate health risks from heat and flooding, as well as other climate-sensitive exposures harmful to human health, including outdoor and indoor air pollution, aeroallergens, vector-borne pathogens, and waterborne contaminants. Key messages from the chapter include: 1. **Heat Waves**: Heat waves are the deadliest type of extreme weather in NYC, causing serious illnesses and deaths. Climate change will lead to more dangerous hot weather, exacerbating chronic health conditions and increasing the risk of heat-related illnesses. 2. **Flooding**: Public health can be impacted before, during, and after flooding, exposing New Yorkers to risks of drowning, injuries, displacement, and exposure to contaminants. Climate projections indicate more frequent and severe flooding. 3. **Air Pollution**: Warmer weather can increase concentrations of harmful air pollutants, affecting all New Yorkers but particularly those with chronic health conditions, low-income households, and those without air conditioning. 4. **Aeroallergens**: Climate change is causing earlier and longer pollen seasons, contributing to seasonal allergic rhinitis and asthma exacerbations, especially in communities with limited access to healthcare. 5. **Vector-Borne Pathogens**: Changes in climate and habitat are shifting the distribution of vectors like mosquitoes and ticks, increasing the risk of diseases like West Nile virus and Lyme disease. 6. **Waterborne Pathogens**: Climate change may increase the risk of exposure to waterborne pathogens, compromising drinking water sources and distribution systems. 7. **Compound Health Risks**: Climate risks can be compounded by lifeline infrastructure disruptions and other public health emergencies, such as the COVID-19 pandemic, creating additional health risks. The chapter also discusses strategies for reducing future climate risks to health, including public health messaging, emergency response, community and social supports, and interventions in housing and energy sectors. It highlights the importance of addressing environmental and social drivers of vulnerability and the need for adaptive measures to protect vulnerable populations.This chapter of the New York City Panel on Climate Change 4 (NPCC4) report focuses on climate health risks, vulnerabilities, and resilience strategies in New York City's unique urban context. It updates evidence since the last health assessment in 2015 and addresses emerging climate health risks and vulnerabilities specific to NYC. The chapter emphasizes climate health risks from heat and flooding, as well as other climate-sensitive exposures harmful to human health, including outdoor and indoor air pollution, aeroallergens, vector-borne pathogens, and waterborne contaminants. Key messages from the chapter include: 1. **Heat Waves**: Heat waves are the deadliest type of extreme weather in NYC, causing serious illnesses and deaths. Climate change will lead to more dangerous hot weather, exacerbating chronic health conditions and increasing the risk of heat-related illnesses. 2. **Flooding**: Public health can be impacted before, during, and after flooding, exposing New Yorkers to risks of drowning, injuries, displacement, and exposure to contaminants. Climate projections indicate more frequent and severe flooding. 3. **Air Pollution**: Warmer weather can increase concentrations of harmful air pollutants, affecting all New Yorkers but particularly those with chronic health conditions, low-income households, and those without air conditioning. 4. **Aeroallergens**: Climate change is causing earlier and longer pollen seasons, contributing to seasonal allergic rhinitis and asthma exacerbations, especially in communities with limited access to healthcare. 5. **Vector-Borne Pathogens**: Changes in climate and habitat are shifting the distribution of vectors like mosquitoes and ticks, increasing the risk of diseases like West Nile virus and Lyme disease. 6. **Waterborne Pathogens**: Climate change may increase the risk of exposure to waterborne pathogens, compromising drinking water sources and distribution systems. 7. **Compound Health Risks**: Climate risks can be compounded by lifeline infrastructure disruptions and other public health emergencies, such as the COVID-19 pandemic, creating additional health risks. The chapter also discusses strategies for reducing future climate risks to health, including public health messaging, emergency response, community and social supports, and interventions in housing and energy sectors. It highlights the importance of addressing environmental and social drivers of vulnerability and the need for adaptive measures to protect vulnerable populations.