Indoor Thermal Environments, Cooling Access, and Energy Burden in New Orleans, LA: Challenges and Opportunities for Heat Adaptation.

Extreme heat is a significant and growing health hazard in urban locations around the world, particularly in the Southeastern United States (U.S.). While most extreme heat research and interventions are focused on ambient outdoor conditions and the neighborhood environment, the indoor residential environment is where the most severe heat-health consequences occur. The aim of this study was to characterize the indoor thermal environments and identify predictors of high indoor temperatures for residents of heat-vulnerable neighborhoods within New Orleans, Louisiana, within the context of current heat adaptation measures and issues of energy insecurity. We conducted surveys with both open- and closed-ended questions and measured indoor temperature over 2-week sampling periods in 114 households across two heat vulnerable New Orleans wards during the warm seasons of 2023 and 2024. Our study found that a combination of AC type and use, along with outdoor daily maximum temperature, were significant predictors of indoor maximum overnight temperature. Our results indicate that households without AC, using window AC units, or those not running central AC all or most of the time struggled to maintain 80 degrees Fahrenheit overnight (a threshold deemed appropriate by a recent healthy homes ordinance) once outdoor daily maximum temperatures exceeded 90 degrees Fahrenheit. Homeownership, compared to renting, was associated with higher overnight indoor temperatures, greater variability in typical AC use patterns, and greater sensitivity of summer monthly energy expenditures to differences in AC use patterns, potentially indicating that this group is practicing energy limiting behavior. This paper contributes to limited literature on indoor thermal environments, particularly in the Southeastern U.S., and underscores the importance of housing and energy burden in heat adaptation.