heat·shed | /ˈhētˌshed/ | noun
1. The spatial and policy area across which extreme heat must be understood and governed as a shared condition — crossing city limits, county lines, and state boundaries, as a watershed does for water. No single jurisdiction controls its own heatshed.
2. A critical turning point at which extreme heat must be rapidly addressed to protect health and livelihoods worldwide. We are living through a heatshed moment.
— After watershed, which holds both senses: the land where all water drains, and the critical moment things change.
Extreme heat is the deadliest weather hazard in the United States, and the least prepared for. It kills more people than hurricanes, floods, and tornadoes, and yet cities and nations devote a fraction of the attention and resources to it that they give to those hazards.
Part of the reason is that heat as a hazard has no edges we can see. A flood has a floodplain. A wildfire has a perimeter. Heat has neither, so it falls through the gaps between the agencies and jurisdictions that would otherwise be responsible for it. The conditions that make a community dangerously hot, such as regional land use, transportation, housing, and energy, are almost never controlled by the government closest to the people being harmed.
The causes of extreme heat exceed political boundaries, and the solutions to address it must span sectors and levels of government.
That is what a heatshed names. It’s the scale at which heat actually operates, and therefore the scale at which it has to be planned for and governed.
Our cities were built for a climate that no longer exists. Planning cities for the climate we have today, and the climate that is coming in the near future, means addressing extreme heat the way we already address water: as a shared regional condition that demands coordinated governance across levels.
Where the term “heatshed” comes from
I introduced the concept of the “heatshed moment” first in my TEDxUofA talk, A “heatshed” moment for communities in crisis. I further made the case for the term in my commentary with Sara Meerow, “Our ‘heatshed’ moment is now” in the Journal of Urban Affairs, which builds on our earlier work defining heat resilience and heat governance.
Cite this
Keith, L., & Meerow, S. (2026). Our “heatshed” moment is now. Journal of Urban Affairs. https://doi.org/10.1080/07352166.2025.2526490