Preventing Health Emergencies And Temperature-related Illness and Deaths Act of 2023 or the Preventing HEAT Illness and Deaths Act of 2023 This bill establishes several programs to address the adverse health effects of extreme heat. For example, the bill establishes an interagency committee in the White House's Office of Science and Technology Policy to address the health risks of extreme heat through coordinated research, strategic partnerships, and workforce development. It also requires the National Oceanic and Atmospheric Administration (NOAA) to (1) establish a heat health information system to improve forecasts of extreme heat, and (2) contract with the National Academies of Sciences, Engineering, and Medicine to study policy, data, and research gaps relating to extreme heat. NOAA may also, in coordination with the interagency committee, award financial assistance to nonprofits, academic institutions, and state, local, and tribal governments to support the ability of communities to mitigate the health effects of extreme heat (e.g., building modifications and educational campaigns).