Table 3.

Overview of studies on indoor thermal conditions and health outcomes in the US.

Ref.	Focus	Method	Participants	Main Measurements	Key Findings
[55]	Indoor and outdoor heat exposure on COPD morbidity	Longitudinal cohort study	69 participants with COPD	Home environmental monitoring (temperature, humidity, indoor air pollutants), daily respiratory health assessments, portable spirometry	Indoor heat is associated with worsened COPD symptoms and increased rescue inhaler use. Effect magnified with higher indoor air pollution. Outdoor heat linked to increased symptoms.
[56]	Indoor environments during emergency medical care	Pilot study, case-control design	338 respiratory cases, 291 cardiovascular cases, 471 controls	Portable sensors for indoor temperature and humidity measurements	Older patients in warmer buildings experienced hotter indoor temperatures. Indoor humidity adjusted to outdoor conditions. No significant difference in indoor heat exposure between cardiovascular cases and controls.
[57]	Indoor temperature control and ambulatory blood pressure	Cross-sectional study	101 normotensive subjects	Ambulatory blood pressure monitoring, interviews, environmental and occupational condition measurements	Seasonal variations in blood pressure, higher in winter. Industrial plant air conditioning influenced seasonal variations.
[58]	BP response and aerobic capacity in hot indoor environment	Observational study	26 community-dwelling older women	Assessment of blood pressure response, aerobic capacity at different room temperatures	Older adults showed lower blood pressure and reduced aerobic capacity in hot indoor conditions.
[59]	Indoor air temperature and agitation in nursing home residents with dementia	Longitudinal study	21 nursing home residents with dementia	Cohen-Mansfield Agitation Inventory (CMAI) for assessing agitated behaviors, measurement of indoor average temperatures	Higher temperatures are associated with increased agitation in residents with dementia. Maintaining thermally comfortable environment recommended.
[61]	Air conditioning during heat waves and cognitive function	Prospective observational cohort study	44 university students	Daily self-administered cognition tests (Stroop, ADD), measurement of indoor temperatures	Non-air-conditioned residents had slower reaction times and reduced cognitive throughput during heat waves. U-shaped relationship between cognitive performance and indoor temperature.
[60]	Indoor temperature, perceptions, and health outcomes	Cross-sectional study	40 New York City apartments	Measurement of indoor temperature and humidity, survey data on perceptions, health outcomes (sleep quality, symptoms)	Perceptions of indoor temperature matched measured temperature. Sleep quality negatively impacted by high indoor temperature. Heat illness symptoms associated with perceived temperature.
[62]	Indoor heat exposure and mortality/morbidity in the elderly	Time-stratified case-crossover study	Elderly individuals (≥65 years) in Houston, Texas	Modeling of summer indoor heat exposure at the U.S. Census block group level, mortality and emergency hospital admission data	Short-term changes in indoor heat linked to increased cause-specific mortality and morbidity among the elderly. Stronger associations observed in African Americans.
[12]	Heat illness and deaths in New York City	Longitudinal study	New York City residents and homeless persons with heat illness diagnosis from 2000 through 2010	De-identified electronic patient records, death certificates, hospital data, medical examiner records	Approximately 447 heat-related emergency department visits, 152 hospital admissions, and 13 heat-related deaths occurred each year in New York City. Higher rates of heat illness and death were associated with older age and neighborhood poverty; chronic physical and mental health conditions were prevalent comorbidities in decedents. 85 % were exposed at home and none of the decedents had a working air conditioner.