Fans, Healthy, Heat Exposure, Young Adults
Conditions
Keywords
indoor temperature, core temperature, heart rate, electric fans, cardiovascular strain
Brief summary
Extreme heat events are a significant global threat to health and wellbeing, and result in more morbidity and mortality than all other natural disasters combined. Thus, a key priority is identifying effective and accessible heat resilience solutions to protect individuals from the potentially fatal consequences of heat stress. Within a range of ambient conditions, a fan has been recognized a low-cost heat resilience solution. However, when ambient temperatures exceed skin temperatures (e.g., above 35°C), a fan will incur greater dry heat gain which may be counterbalanced with evaporation of sweat from the skin surface. However, at a critical indoor temperature, the rate of heat gain will exceed the rate of evaporation resulting in net heat gain. The critical indoor temperature has yet to be determined. The purpose of this present study is to identify the indoor temperature at which a fan results in greater cardiovascular and thermal strain relative to still air in young adults using a simulated heat wave scenario of a warming room.
Interventions
OTHERTemperature Ramp Protocol
Following a 45 minute baseline in 37°C seated on a chair, the indoor temperature in the climate-controlled room increased from 37°C to 47°C at \ 0.06°C/min (relative humidity \ 26%) over 180 minutes.
Sponsors
Lakehead University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
19 Years to 39 Years
Healthy volunteers
Yes
Inclusion criteria
* Body mass index less than 30 * male or female * ability to tolerate hot environments for a prolonged period (e.g. >2 h)
Exclusion criteria
* Any respiratory disease * Any cardiovascular disease, including hypertension * Diabetes * not currently on any medication (except oral contraceptives)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Whole-Body Sweat Rate | At baseline (e.g. 0 minutes), and every minute for the 180 minute experimental trial | Net difference in body mass (pre versus post) using a balance scale placed below the chair of the participant |
| Skin Temperature | At baseline (e.g. 0 minutes), and every minute for the 180 minute experimental trial | Measured at 4 skin locations (chest, arm, thigh, and calf) using wireless iButtons affixed to the skin with surgical tape |
| Core Temperature | At baseline (e.g. 0 minutes), and every minute for the 180 minute experimental trial | rectal temperature measured with a pediatric grade thermistor probe |
| Blood Pressure | At baseline (e.g. 0 minutes), and every 10 minutes of exposure up to 180 minutes | Measured with an electrocardiogram-gated automated cuff |
| Rate Pressure Product | At baseline (e.g. 0 minutes), and every 10 minutes of exposure up to 180 minutes | — |
| Heart Rate | At baseline (e.g. 0 minutes), and every minute for the 180 minute experimental trial | Measured with a 3-lead electrocardiogram |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Thermal comfort | Assessed at baseline (e.g. 0 minutes), and every 10 minutes for the 180 minute experimental trial | visual analog scale |
| Thermal Sensation | At baseline (e.g. 0 minutes), and every 10 minutes for the 180 minute experimental trial | visual analog scale |
Countries
Canada
Outcome results
None listed