Thermal Sensation in Older People with and without Dementia Living in Residential Care: New Assessment Approaches to Thermal Comfort Using Infrared Thermography

Abstract

The temperature of the indoor environment is important for health and wellbeing, especially at the extremes of age. The study aim was to understand the relationship between self-reported thermal sensation and extremity skin temperature in care home residents with and without dementia. The Abbreviated Mental Test (AMT) was used to discriminate residents to two categories, those with, and those without, dementia. After residents settled and further explanation of the study given (approximately 15 min), measurements included: tympanic membrane temperature, thermal sensation rating and infrared thermal mapping of non-dominant hand and forearm. Sixty-nine afebrile adults (60–101 years of age) were studied in groups of two to five, in mean ambient temperatures of 21.4–26.6 °C (median 23.6 °C). Significant differences were observed between groups; thermal sensation rating (p = 0.02), tympanic temperature (p = 0.01), fingertip skin temperature (p = 0.01) and temperature gradients; fingertip-wrist p = 0.001 and fingertip-distal forearm, p = 0.001. Residents with dementia were in significantly lower air temperatures (p = 0.001). Although equal numbers of residents per group rated the environment as ‘neutral’ (comfortable), resident ratings for ‘cool/cold’ were more frequent amongst those with dementia compared with no dementia. In parallel, extremity (hand) thermograms revealed visual temperature demarcation, variously across fingertip, wrist, and forearm commensurate with peripheral vasoconstriction. Infrared thermography provided a quantitative and qualitative method to measure and observe hand skin temperature across multiple regions of interest alongside thermal sensation self-report. As an imaging modality, infrared thermography has potential as an additional assessment technology with clinical utility to identify vulnerable residents who may be unable to communicate verbally, or reliably, their satisfaction with indoor environmental conditions.

Thermal comfort modelling of older people living in care homes: An evaluation of heat balance, adaptive comfort, and thermographic methods

“…As discussed by Hoof et al [15] and Childs et al [21], there is a clear need for easily deployable techniques to allow carers to make timely assessments and for them to take adequate actions to help the resident to achieve thermal comfort. Currently, there lacks a reliable indicator to determine a person's thermal sensations physiologically without the need to ask.…”

“…Childs et al [21] present a case for using IRT to 'see' the thermal map of the extremities and to deduce the corresponding thermal sensation vote. The principle here is that, (under thermally neutral conditions) skin blood flow in the hands is tonically active such that vasomotor tone of skin capillaries operates as the primary 'controller' of deep body temperature.…”

“…Based on available studies [21,22], ASHRAE [47] state that the PMV model for thermal comfort assessment is applicable for young and old alike. This, it is claimed, is because metabolic rate clothing choices account for the effects of age (and gender) in PMV estimations [12].…”

“…The field survey and data measurements were performed by Childs et al [21] with participation from 69 older residents (60-101 years of age) living in 15 residential care homes within the South Yorkshire and Derbyshire counties of the UK, over a 12-month period (June 2017 -June 2018).…”

“…How this is achieved in the setting of residential care presents a major challenge for residents with advanced age or health conditions, specifically with respect to their ability to perceive a change in the thermal conditions of their immediate environment which, day to day, is typically controlled entirely by younger staff [15]. In addition, care home residents with dementia may be unable to communicate verbally, or reliably, their satisfaction with indoor environmental conditions [21].…”