title: Heat-related thermal sensation, comfort and symptoms in a northern population: the National FINRISK 2007 study.
abstract: BACKGROUND
  The occurrence of subjective symptoms related to heat strain in the general population is unknown. The present study aimed to describe the temperatures considered to be comfortable or hot and the prevalence of heat-related complaints and symptoms in the Finnish population.
  
  
  METHODS
  Four thousand and seven men and women aged 25-74 years, participants of the National FINRISK 2007 study, answered a questionnaire inquiring about the ambient temperatures considered to be hot and the upper limit of comfortable and about heat-related complaints and symptoms. The age trends in threshold temperatures and symptom prevalence were examined in 1-year groups by gender after smoothing with loess regression. The prevalence estimates were also adjusted for age.
  
  
  RESULTS
  The temperature considered as hot averaged 26°C and the upper limit for thermal comfort was 22°C. Both temperatures declined with age (from 25 to 74 years) by 1-5°C. Approximately 80% of the subjects reported signs or symptoms of heat strain in warm weather, mostly thirst (68%), drying of mouth (43%), impaired endurance (43%) and sleep disturbances (32%). Cardiac and respiratory symptoms were reported by 6 and 7%, respectively, and their prevalence increased up to the age of 75 years. The exception was thirst, whose prevalence declined with age. Most symptoms and complaints were more prevalent in women than men.
  
  
  CONCLUSIONS
  A large percentage of this northern European population suffers from heat-related complaints. Information on these is an aid in assessing the burden of summer heat on population health and is a prerequisite for any rational planning of pre-emptive measures.
authors.affiliation: 1 Institute of Health Sciences, University of Oulu, Oulu, Finland2 Center for Environmental and Respiratory Health Research, University of Oulu, Oulu, Finland3 Finnish Institute of Occupational Health, Oulu, Finland simo.nayha@oulu.fi.
authors.forename: Simo
authors.initials: S
authors.lastname: Näyhä
authors.affiliation: 3 Finnish Institute of Occupational Health, Oulu, Finland4 Institute of Biomedicine, University of Oulu, Oulu, Finland.
authors.forename: Hannu
authors.initials: H
authors.lastname: Rintamäki
authors.affiliation: 5 Centre for Respiratory Medicine, University College London, London, UK.
authors.forename: Gavin
authors.initials: G
authors.lastname: Donaldson
authors.affiliation: 1 Institute of Health Sciences, University of Oulu, Oulu, Finland2 Center for Environmental and Respiratory Health Research, University of Oulu, Oulu, Finland.
authors.forename: Juhani
authors.initials: J
authors.lastname: Hassi
authors.affiliation: 6 National Institute for Health and Welfare, Helsinki, Finland.
authors.forename: Pekka
authors.initials: P
authors.lastname: Jousilahti
authors.affiliation: 6 National Institute for Health and Welfare, Helsinki, Finland7 Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland8 Hospital District of North Karelia, Joensuu, Finland.
authors.forename: Tiina
authors.initials: T
authors.lastname: Laatikainen
authors.affiliation: 1 Institute of Health Sciences, University of Oulu, Oulu, Finland2 Center for Environmental and Respiratory Health Research, University of Oulu, Oulu, Finland9 Respiratory Medicine Unit, Department of Medicine, Oulu University Hospital, Oulu, Finland.
authors.forename: Jouni J K
authors.initials: JJ
authors.lastname: Jaakkola
authors.affiliation: 1 Institute of Health Sciences, University of Oulu, Oulu, Finland2 Center for Environmental and Respiratory Health Research, University of Oulu, Oulu, Finland.
authors.forename: Tiina M
authors.initials: TM
authors.lastname: Ikäheimo
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D005260:Female; D005387:Finland / Q000453:epidemiology; D018882:Heat Stress Disorders / Q000503:physiopathology; D006358:Hot Temperature / Q000009:adverse effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011795:Surveys and Questionnaires; D013697:Thermosensing / Q000502:physiology