Effect of Ceiling Fans on Core Temperature in Bed-Resting Older Adults Exposed to Indoor Overheating

Q: What was the study’s primary goal?

To evaluate whether ceiling fans reduce peak core temperature and cardiovascular strain during simulated indoor overheating in bed-resting older adults.

Q: How were ceiling fans tested in the study?

Participants completed two randomized 8-hour exposures at 31°C and 45% relative humidity with ceiling-fan air speeds set to 0 m/s (control) or about 1.5 m/s (fan condition).

Q: Did ceiling fans fully prevent heat-related physiological strain?

No. Fan use significantly lowered heat-related strain measures, but it did not fully ameliorate heat-induced physiological strain under the tested conditions.

Sep 29, 2026

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Rising indoor temperatures elevate heat-overheating risks, especially for older adults who are bed-resting. Electric fans are commonly recommended up to 40°C, yet evidence for ceiling-fan performance at very warm conditions around 31°C is limited. This randomized crossover study tested whether ceiling fans reduce core temperature and cardiovascular strain during 8-hour exposures to simulated indoor overheating (31°C, 45% RH).

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages5

Reading Time13 min

AccessFree to download

Abstract

Background

Methods

Results

Conclusions

Introduction

Methods

Journal of the American Geriatrics Society Journal of the American Geriatrics Society Effect of Ceiling Fans on Core Temperature in Bed-Resting Older Adults Exposed to Indoor Overheating Fergus K. O'Connor1,2 | Robert D. Meade1,3 | Kristina-Marie T. Janetos1 | Caroline Li-Maloney1 | Ronald J. Sigal1,4,5,6,7 | Pierre Boulay8 | Glen P. Kenny1,7 1Human and Environmental Physiology Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, Ontario, Canada | 2School of Health Sciences and Social Work, Griffith University, Southport, Queensland, Australia | 3Department of Epidemiology, T.H. Chan School of Public Health, Harvard University, Boston, Massachusetts, USA | 4Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada | 5Department of Cardiac Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada | 6Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada | 7Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Canada | 8Faculty of Physical Activity Sciences, University of Sherbrooke, Sherbrooke, Quebec, Canada Correspondence: Glen P. Kenny ([gkenny@uottawa.ca](gkenny@uottawa.ca)) Received: 25 June 2025 | Revised: 7 August 2025 | Accepted: 14 August 2025 Funding: This work was supported by Health Canada (4500387992) and Canadian Institutes of Health Research (PJT-180242) . Keywords: extreme heat event | heat stress | sustainable cooling | thermoregulation ABSTRACT Background: Rising global temperatures have increased indoor overheating risks, posing significant health threats to vulnerable populations, particularly older adults. While electric fans are recommended for cooling at temperatures up to 40°C, the efficacy of ceiling fans in very warm indoor temperatures (~31°C) remains understudied. This randomized study evaluated the efficacy of ceiling fans in reducing core temperature and cardiovascular strain among bed-resting adults exposed to simulated indoor overheating (31°C, 45% relative humidity) for 8 h. Methods: Twenty participants (12 females, median [IQR] age: 71 [68–73] years) underwent two experimental exposures with a ceiling fan set at either 0 m/s (control) or ~1.5 m/s (fan condition) . Results: The primary outcome, peak core temperature, was significantly lowered by 0.2 [95% CI: 0.1–0.3]°C (0.4 [0.2–0.5]°F, p < 0.001) with fan use (mean [SD]) 37.6 [0.2]°C (99.7 [0.4]°F); +0.9 [0.3]°C (+1.6 [0.5]°F) vs. pre-exposure) compared to control (37.8 [0.2]°C (100.0 [0.4]°F); +1.1 [0.5]°C (+2.0 [0.9]°F) vs. pre-exposure) . Secondary outcomes, including core temperature area under the curve, peak and end-exposure heart rate, fluid consumption, and thermal discomfort, were also reduced significantly with fan use. Despite these improvements, fan use did not completely ameliorate heat-induced physiological strain. Conclusions: These findings indicate that while ceiling fans significantly reduce heat-related physiological strain under the conditions tested, they are not wholly efficacious as standalone cooling solutions. A combined “fan-first” approach, integrating fans with ambient cooling strategies, may enhance heat–health protection in older adults. ClinicalTrials.Gov Identifier: NCT06142890 1 | Introduction Rising global temperatures are increasing the incidence of indoor overheating and accompanying health risks [1], with older adults (≥65years) and those living alone or confined to bed most at risk [2] . While electric fans are recommended in air temperatures up to 40°C [3], studies utilizing pedestal fans at 36°C–38°C (96.8°F–100.4°F) have reported only minor, non-clinically This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the us

FAQs

What was the study’s primary goal?

To evaluate whether ceiling fans reduce peak core temperature and cardiovascular strain during simulated indoor overheating in bed-resting older adults.

How were ceiling fans tested in the study?

Participants completed two randomized 8-hour exposures at 31°C and 45% relative humidity with ceiling-fan air speeds set to 0 m/s (control) or about 1.5 m/s (fan condition).

Did ceiling fans fully prevent heat-related physiological strain?

No. Fan use significantly lowered heat-related strain measures, but it did not fully ameliorate heat-induced physiological strain under the tested conditions.

Sep 29, 2026

Upload by jayni