title: The effect of high indoor temperatures on self-perceived health of elderly persons.
abstract: BACKGROUND
  Exposure to high ambient temperatures leads to an increase in mortality and morbidity, especially in the elderly. This relationship is usually assessed with outdoor temperature, even though the elderly spend most of their time indoors. Our study investigated the relationship between indoor temperature and heat-related health problems of elderly individuals.
  
  
  METHODS
  The study was conducted in the Netherlands between April and August 2012. Temperature and relative humidity were measured continuously in the living rooms and bedrooms of 113 elderly individuals. Respondents were asked to fill out an hourly diary during three weeks with high temperature and one cold reference week, and a questionnaire at the end of these weeks, on health problems that they experienced due to heat.
  
  
  RESULTS
  During the warmest week of the study period (14-20 August), average living room and bedroom temperatures were approximately 5°C higher than during the reference week. More than half of the respondents perceived their indoor climate as too warm during this week. The most reported symptoms were thirst (42.7%), sleep disturbance (40.6%) and excessive sweating (39.6%). There was a significant relationship between both indoor and outdoor temperatures with the number of hours that heat-related health problems were reported per day. For an increase of 1°C of indoor temperature, annoyance due to heat and sleep disturbance increased with 33% and 24% respectively. Outdoor temperature was associated with smaller increases: 13% and 11% for annoyance due to heat and sleep disturbance, respectively. The relationship between outdoor temperature and heat-related health problems disappeared when indoor and outdoor temperatures were included in one model.
  
  
  CONCLUSIONS
  The relationship with heat-related health problems in the elderly is stronger with indoor (living room and bedroom) temperature than with outdoor temperature. This should be taken into account when looking for measures to reduce heat exposure in this vulnerable group.
authors.affiliation: Public Health Services Gelderland-Midden, Arnhem, The Netherlands; Centre for Research on the Epidemiology of Disasters (CRED), Université Catholique de Louvain, Brussels, Belgium. Electronic address: joris.vanloenhout@uclouvain.be.
authors.forename: J A F
authors.initials: JA
authors.lastname: van Loenhout
authors.affiliation: Municipal Health Services Groningen, Groningen, The Netherlands. Electronic address: amanda.legrand@ggd.groningen.nl.
authors.forename: A
authors.initials: A
authors.lastname: le Grand
authors.affiliation: Municipal Health Services Groningen, Groningen, The Netherlands. Electronic address: frans.duijm@ggd.groningen.nl.
authors.forename: F
authors.initials: F
authors.lastname: Duijm
authors.affiliation: Municipal Health Services Groningen, Groningen, The Netherlands. Electronic address: frans.greven@ggd.groningen.nl.
authors.forename: F
authors.initials: F
authors.lastname: Greven
authors.affiliation: Municipal Health Services Groningen, Groningen, The Netherlands. Electronic address: nienke.vink@ggd.groningen.nl.
authors.forename: N M
authors.initials: NM
authors.lastname: Vink
authors.affiliation: Division of Environmental Epidemiology, Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands. Electronic address: g.hoek@uu.nl.
authors.forename: G
authors.initials: G
authors.lastname: Hoek
authors.affiliation: Public Health Services Gelderland-Midden, Arnhem, The Netherlands. Electronic address: moniek.zuurbier@vggm.nl.
authors.forename: M
authors.initials: M
authors.lastname: Zuurbier
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006304:Health Status; D006358:Hot Temperature / Q000009:adverse effects*; D006798:Housing; D006801:Humans; D009426:Netherlands; D011446:Prospective Studies; D012621:Seasons; D057566:Self Report
keywords: Climate change; Elderly; Heat; Indoor temperature; Symptoms