California Heat & Health Project

California's Fourth Climate Change Assessment

As part of California’s Fourth Climate Change Assessment, Four Twenty Seven is working with project partners to develop a tool that will inform long-term planning efforts to communicate the urgency of and mitigate the public health impacts of increasing extreme heat events across the state.

The Challenge of Heat Events in California

The number of extreme heat days in California are projected to increase from currently around ten a year to 25-50 by 2050, and upwards of 100 by the end of the century. Extreme heat has major impacts on human health, especially on the most vulnerable populations.

The California Heat & Health Project is funded by the California Energy Commission as part of the California Fourth Climate Change Assessment to develop an interactive, user-friendly tool that will provide public health and planning stakeholders with detailed projections on extreme heat events and the potential health impacts for local communities.

User Needs Report

California Heat & Health Project: A Decision Support ToolTo better inform this tool, we conducted a robust literature review and user needs assessment to understand how the California Heat and Health Project can best inform and improve current efforts in all California regions. Our report outlines our key findings from this research including results from an online survey and interviews with public health, planning and emergency preparedness stakeholders throughout California.

Our research shows the limitations of emergency response to prevent the health impacts of heat waves. The greatest strides can be made through interventions planned well ahead of time, such as changes in the urban design and social programs. Therefore, we conclude that a new online decision support tool is best geared towards informing mid and long-term interventions to reduce the public health impacts of extreme heat.

The online decision support tool is currently in development, and will be available in the fall of 2017 through Cal-Adapt, the state’s adaptation portal.

Download the report



Founded in 2012, Four Twenty Seven is an award-winning climate risk and resilience research and advisory firm that brings climate intelligence to economic and financial decision-makers. Four Twenty Seven helps investorsFortune 500 companies and government institutions understand how to quantify and monetize climate change impacts on operations as well as social factors that affect their value chain. Customers rely on Four Twenty Seven’s tools and models to factor into financial and operational planning processes. Four Twenty Seven’s team is comprised of highly qualified professionals with backgrounds in climate science, economics and finance, natural resources management, policy analysis, public health, and international development.