Efficacy of Electric Fans in Children During Heat Waves
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age9-25
SponsorUniversity of Ottawa
About this trial
Extreme heat exposure is an escalating global public health concern, with climate change driving increases in the frequency, duration, and intensity of heat events. Projections indicate substantial increases in heat-related morbidity and mortality in the coming decades, including among children and youth, who are increasingly recognized as a physiologically vulnerable population. The purpose of this project is to evaluate the effectiveness of commonly used heat-mitigation strategies, specifically midday access daylong electric fan use, in reducing physiological strain and maintaining cognitive function, perceptual comfort, and psychological well-being in children and youth exposed to prolonged indoor heat. The study also aims to determine whether these strategies provide comparable protection in children and youth relative to young adults. Participants will complete four sessions under the same environmental conditions (31°C and 36°C), with each temperature completed twice: once with continuous electric fan use and once without fan use. The four sessions therefore consist of: (1) 31°C without fan use; (2) 31°C with fan use; (3) 36°C without fan use; and (4) 36°C with fan use.
Eligibility criteria
This trial accepts healthy volunteersQualifiers
Participants must be healthy males or females within the specified age ranges (9-12 years, 13-16 years, or 20-25 years).
All participants must be habitually active, defined as participation in regular physical activity at least three times per week for a minimum of 20 minutes per session over the previous six months.
Participants must be able to understand and communicate in English or French.
For participants under 18 years of age, written parental or guardian consent and participant assent will be required prior to participation.
Disqualifiers
Individuals will be excluded from participation if they have any acute illness at the time of testing (e.g., cold, flu, or infection), or a history of chronic medical conditions that may affect thermoregulation, cardiovascular function, or exercise capacity, including but not limited to cardiovascular, metabolic, respiratory, or neurological disorders. Individuals taking medications known to influence thermoregulation, hydration status, or cardiovascular responses will also be excluded.
Participants with a history of heat-related illness (e.g., heat exhaustion or heat stroke) will not be eligible.
Individuals with digestive abnormalities or gastrointestinal conditions that may contraindicate ingestion of a telemetry pill will also be excluded.
Any individual who, in the opinion of the investigators, may be at increased risk or unable to safely complete the study procedures will be excluded.
Trial design
Design model
Crossover
Treatments tested in this trial
Simulated exposure to indoor overheating without fans
Other interventionChildren and young adults exposed to a 6-hour simulated heat exposure without fans.
Simulated exposure to indoor overheating with fans
Other interventionChildren and young adults exposed to a 6-hour simulated heat exposure without fans.
Treatment groups
60 Participants
are divided into 4 treatment groupsGroup A: Warm indoor environment of 31°C without fansExperimental treatment 1 intervention
Group B: Warm indoor environment of 31°C with fansExperimental treatment 1 intervention
Group C: Hot indoor environment of 36°C without fansExperimental treatment 1 intervention
Group D: Hot indoor environment of 36°C with fansExperimental treatment 1 intervention
Trial outcomes
Primary outcomes
1
Core temperature (Peak) during daylong exposure to indoor overheating
Peak core (indexed by visceral temperature) temperature (15 min average) during exposure. Visceral temperature is measured continuously throughout the 6 hour exposure to the simulated indoor overheating.
Time frame
End of 6 hour daylong exposureSecondary outcomes
1
Profiles of Mood States (POMS) during daylong exposure to indoor overheating
Potential changes in mood (7 subscales of mood: tension, anger, depression, fatigue, confusion, vigor and esteem related affect). The POMS-40 is a validated, self-administered questionnaire that examines seven distinct aspects of mood state across two positive subscales (Esteem-Related Affect, and Vigor) and five negative subscales (Fatigue, Tension, Confusion, Anger, and Depression), which are described across 40 distinct adjectives. For each individual item, participants are asked to describe "how you feel right now" by responding using a 5-point Likert scale (0 = "Not at all", 1 = "A little", 2 = "Moderately", 3 = "Quite a lot", or 4 = "Extremely"). The values of items associated with a specific subscale (e.g., Fatigue) are summed to calculate its score.
Time frame
At the start (hour 0) and end of 6 hour daylong exposure2
Environmental Symptoms Questionnaire (ESQ) during daylong exposure to indoor overheating
Self-reported environmental reactions and medical symptomatology associated with prolonged heat exposure. The ESQ-IV is a validated 68-item, self-administered questionnaire that has been used successfully in identifying symptomatology during exposure to a wide variety of environmental conditions, including heat exposure. Participants are asked to assess and described "how you have been feeling today" by responding to each item using a 6-point Likert scale (0 = "Not at all", 1 = "Slight", 2 = "Somewhat", 3 = "Moderate", 4 = "Quite a bit", or 5 = "Extreme"). Total Symptom Score is calculated from this data by taking the sum of the intensity ratings from all 68 individual items using reverse scores for the three positive items from the list ("I Felt Good", "I Felt Alert", and "I Felt Wide Awake").
Time frame
At the start (hour 0) and end of 6 hour daylong exposure3
Perceived exertion scale during daylong exposure to indoor temperature limit
Perceived exertional assessed via an ordinal scale ("How hard are you working?") ranging from "no exertional at all" to "maximal exertion"
Time frame
At the start (hour 0) and end of 6 hour daylong exposure4
Activity levels (total steps taken) during daylong exposure to indoor overheating
Activity levels, quantified by number of steps taken per hour and totaled for each 6 hour exposure, assessed via a wearable accelerometer worn on the wrist and hip.
Time frame
End of 6 hour daylong exposureSponsors and contacts
Click on the lead sponsor to view all of their trials.
Source ClinicalTrials.gov