Environmental ExposureIEQ-HUMNCT05972187
The Effect of IEQ on Cognition and Health
A study testing Temperature and Humidity in people with Environmental Exposure and Temperature Change, Body, run by Maastricht University Medical Center at 1 site in Netherlands.
Trial summary
The goal of this study is to learn about the effect of heat and humidity on cognition and health. The main question[s] it aims to answer are: type of study: interventional participant population: 20-40years, both gender, healthy Participants will be exposed for 4 different sessions of 8 hours at a time, to 32˚ C or… Read more about this study
- Who is it for?
- Ages 20 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- Environmental Exposure, Temperature Change, Body, Condition
- What is being tested?
- Temperature and Humidity
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 22 participants
- Where
- 1 siteNetherlands
- Study dates
- 18 Jun 2023to 7 May 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 20 to 40 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- BMI between 18.5-26 kg/m2
- Age between 20-40 years
- Proficient with the English language in both verbal and written form
- Healthy; no illness or disease or prescribed medication within the last 3 months
- Steady dietary and sleeping habits
- Regularly physically active (i.e., regularly active but less than 3 times a week for less than 2 hours per session at moderate intensity)
- Non-smoker or person who quit smoking more than five years ago
- Reside in the Netherlands (or surrounding countries) for at least 6 months
Who cannot join
- Subjects with cardiac problems and cardiovascular diseases, such as angina pectoris, cardiac infarction, and arrhythmias
- Subjects with any medical condition requiring treatment and/or medication (except oral contraceptives) that might interfere with the investigated parameters E.g., Extreme chronotype, colour blindness, epilepsy
- Subjects with a disorder or disease (Parkinson, Attention Deficit Hyperactivity Disorder (ADHD), Alzheimer, diabetes, cardiovascular disorder, respiratory impairments (for example asthma), hypertension, obesity, or any other condition that can impair the lung function), or Raynaud's phenomenon
- Subjects with abnormal diet and sleeping patters and/or abnormal body weight (weight gain or loss >3kg in the past month)
- Subjects who recently participated in other interventional biomedical study within 1 month prior to screening visit
- Subjects, who do not want to be informed about unexpected medical findings, or do not wish that their treating physician will be informed, cannot participate in this study
Show all 12Show fewer
- Subjects with previous covid infection in the past 3 months or any subject with persistent long covid symptoms that may have caused ongoing loss of or altered sense of smell
- Subjects who had severely altered sleep patterns in the past year
- Subjects employed with night shift work within the past year
- Subjects who consume more than two standard drinks of alcohol per day
- Subjects who consume more than two standard drinks of coffee per day
- Subjects who are pregnant
Trial locations and contacts
1 site in 1 country.
About this study
Official title: The Effect of the Indoor Environmental Quality (IEQ) on Cognition and Health
The goal of this study is to learn about the effect of heat and humidity on cognition and health. The main question[s] it aims to answer are:
type of study: interventional participant population: 20-40years, both gender, healthy Participants will be exposed for 4 different sessions of 8 hours at a time, to 32˚ C or 25˚ C in combination with relative humidity of 30 %RH or 70 %RH.
Read the detailed description
Overall, the project aims to evaluate the effects of high vs. neutral temperature (32˚ C vs. 25˚ C) in combination with high vs. low humidity (30 %RH vs. 70 %RH) on cognition, for longer exposure duration (8 hours). Deviations from the personal comfort zones are expected to affect both subjective feelings and physiological parameters. Therefore, the following parameters will be included: cognition, environmental perception, energy expenditure, body temperatures.
Main research question and primary objective:
What is the impact of being exposed for 8 hours to a high humidity (RH 70%) versus low humidity (RH 30%) on cognitive performance of individuals if the room temperature is 25ºC or 32ºC?
This leads to the following hypotheses:
- Exposure to an indoor high relative humidity (RH 70%) at a warm temperature (32ºC) of a long duration (8 hours) reduces the composite score, speed and accuracy of cognitive performance compared to an exposure to a low RH (30%) at the same temperature (32ºC) due to the humidity.
- An exposure to an indoor high relative humidity (RH 70%) at a neutral temperature (25ºC) of a long duration (8 hours) would reduce the composite score, speed and accuracy of cognitive performance compared to an exposure to a low RH (30%) at a neutral temperature (25 ºC) due to previous literature for humidity influences at neutral temperatures.
Secondary research question and secondary objective:
What is the effect of high vs. neutral temperature (32˚ C vs. 25˚ C) in combination with high vs. low humidity (30 %RH vs. 70 %RH) on physiological responses, environmental perception, decision making, and bias behaviour?
This leads to the following hypotheses:
- Does an 8 hour exposure to an elevated concentration of indoor humidity lead to an increase in energy expenditure and/or a greater difference in proximal and distal blood flow and skin temperature gradients compared to a lower indoor humidity for each of the temperature settings?
- What are the effects of high humidity on substrate oxidation, blood pressure, heart rate variability, proximal and distal skin temperature, risk behavior and decision-making responses of individuals?
- What are the effects of higher humidity on environmental perception (thermal, air quality, moisture/wetness) comfort, perception, and sensation?
- An exposure to an indoor high relative humidity (RH 70%) at a warm temperature (32ºC) of a long duration (8 hours) reduces the composite score, speed and accuracy of cognitive performance compared to an exposure to a high RH (70%) at a neutral temperature (25 ºC) due to the humidity and temperature.
- An exposure to an indoor low relative humidity (RH 30%) at a warm temperature (32ºC) of a long duration (8 hours) would reduce the composite score, speed and accuracy of cognitive performance compared to an exposure to the same low RH (30%) at a neutral temperature (25 ºC) due to the temperature.
Exploratory research question and objective:
What is the interaction effect of high vs. neutral temperature (32˚ C vs. 25˚ C) in combination with high vs. low humidity (30 %RH vs. 70 %RH) on cognitive performance, physiological responses, environmental perception, decision making, and bias behaviour?
- Conditions
- Environmental Exposure, Temperature Change, Body, Condition, Healthy
- Being tested
- Temperature and Humidity
- Keywords
- Temperature, Humidity, Thermoregulation, Cognition, Health
- Medical subject headings
- Body Temperature Changes, Disease
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Temperature and HumidityOther
Temperature and Humidity of room changed
| Study group | Role | What they receive |
|---|---|---|
| Temperature and Humidity | Experimental | 32C or 25C and 30%RH or 70%RH Receives: Other: Temperature and Humidity |
What is being measured
The primary outcome is the main question the study is designed to answer.
Cognition
Using a tablet based cognitive test battery
Measured: 1 month
Secondary outcomes (5)
Heart Rate (bpm)
Heart Rate measured using Polar heart rate belt in (bpm) with RR and ECG data extracted
Measured: 1 month
Blood pressure (mmHg)
Blood pressure - both systolic and diastolic pressures measured hourly using an automated blood pressure monitor and cuff
Measured: 1 month
Metabolic Rate (ml O2//min/kg)
Metabolic rates measured through whole room calorimetry
Measured: 1 month
Skin Temperature (C)
Skin temperature measured using thermochron (ibuttons) at multiple sites
Measured: 1 month
Body Core Temperature (C)
Core Temperature measured via telemetric pill ingested in the morning
Measured: 1 month
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Aug 2023
- Study start18 Jun 2023
- Primary completion7 May 2024
- Study completion7 May 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Environmental ExposureStudies of the same condition, open and under way.
- More trials run by Maastricht University Medical CenterThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 22 participants (actual)
Sponsor and investigators
- Lead sponsor
- Maastricht University Medical Center
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Guy Plasqui, PHD, Principal investigator, Maastricht University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05972187
- Sponsor's protocol ID
- NL81104.068.22
- Acronym
- IEQ-HUM
- Status last verified
- Sep 2023
- First submitted
- 24 Mar 2023
- Last updated
- 24 Mar 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: If requested raw data will be provided.
Study at a glance
From the registry record, last updated by the sponsor on 24 Mar 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect of the Indoor Environmental Quality (IEQ) on Cognition and Health
- ClinicalTrials.gov ID
- NCT05972187
- Acronym / sponsor ID
- IEQ-HUM / NL81104.068.22
- Conditions
- Environmental Exposure, Temperature Change, Body, Condition, Healthy
- Keywords
- Temperature, Humidity, Thermoregulation, Cognition, Health
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 22 participants (actual)
- Lead sponsor
- Maastricht University Medical CenterUniversity, hospital or other
- Study start
- 18 Jun 2023 (actual)
- Primary completion
- 7 May 2024 (actual)
- Study completion
- 7 May 2024 (actual)
- First posted
- 2 Aug 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this study is to learn about the effect of heat and humidity on cognition and health. The main question[s] it aims to answer are:
type of study: interventional participant population: 20-40years, both gender, healthy Participants will be exposed for 4 different sessions of 8 hours at a time, to 32˚ C or 25˚ C in combination with relative humidity of 30 %RH or 70 %RH.
Detailed description
Overall, the project aims to evaluate the effects of high vs. neutral temperature (32˚ C vs. 25˚ C) in combination with high vs. low humidity (30 %RH vs. 70 %RH) on cognition, for longer exposure duration (8 hours). Deviations from the personal comfort zones are expected to affect both subjective feelings and physiological parameters. Therefore, the following parameters will be included: cognition, environmental perception, energy expenditure, body temperatures.
Main research question and primary objective:
What is the impact of being exposed for 8 hours to a high humidity (RH 70%) versus low humidity (RH 30%) on cognitive performance of individuals if the room temperature is 25ºC or 32ºC?
This leads to the following hypotheses:
- Exposure to an indoor high relative humidity (RH 70%) at a warm temperature (32ºC) of a long duration (8 hours) reduces the composite score, speed and accuracy of cognitive performance compared to an exposure to a low RH (30%) at the same temperature (32ºC) due to the humidity.
- An exposure to an indoor high relative humidity (RH 70%) at a neutral temperature (25ºC) of a long duration (8 hours) would reduce the composite score, speed and accuracy of cognitive performance compared to an exposure to a low RH (30%) at a neutral temperature (25 ºC) due to previous literature for humidity influences at neutral temperatures.
Secondary research question and secondary objective:
What is the effect of high vs. neutral temperature (32˚ C vs. 25˚ C) in combination with high vs. low humidity (30 %RH vs. 70 %RH) on physiological responses, environmental perception, decision making, and bias behaviour?
This leads to the following hypotheses:
- Does an 8 hour exposure to an elevated concentration of indoor humidity lead to an increase in energy expenditure and/or a greater difference in proximal and distal blood flow and skin temperature gradients compared to a lower indoor humidity for each of the temperature settings?
- What are the effects of high humidity on substrate oxidation, blood pressure, heart rate variability, proximal and distal skin temperature, risk behavior and decision-making responses of individuals?
- What are the effects of higher humidity on environmental perception (thermal, air quality, moisture/wetness) comfort, perception, and sensation?
- An exposure to an indoor high relative humidity (RH 70%) at a warm temperature (32ºC) of a long duration (8 hours) reduces the composite score, speed and accuracy of cognitive performance compared to an exposure to a high RH (70%) at a neutral temperature (25 ºC) due to the humidity and temperature.
- An exposure to an indoor low relative humidity (RH 30%) at a warm temperature (32ºC) of a long duration (8 hours) would reduce the composite score, speed and accuracy of cognitive performance compared to an exposure to the same low RH (30%) at a neutral temperature (25 ºC) due to the temperature.
Exploratory research question and objective:
What is the interaction effect of high vs. neutral temperature (32˚ C vs. 25˚ C) in combination with high vs. low humidity (30 %RH vs. 70 %RH) on cognitive performance, physiological responses, environmental perception, decision making, and bias behaviour?
Study design
- Primary purpose
- Other
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Temperature and Humidity | Experimental | Other: Temperature and Humidity32C or 25C and 30%RH or 70%RH |
Who may qualify
- Ages
- 20 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (8 listed)
- BMI between 18.5-26 kg/m2
- Age between 20-40 years
- Proficient with the English language in both verbal and written form
- Healthy; no illness or disease or prescribed medication within the last 3 months
- Steady dietary and sleeping habits
Key exclusion criteria (12 listed)
- Subjects with cardiac problems and cardiovascular diseases, such as angina pectoris, cardiac infarction, and arrhythmias
- Subjects with any medical condition requiring treatment and/or medication (except oral contraceptives) that might interfere with the investigated parameters E.g., Extreme chronotype, colour blindness, epilepsy
- Subjects with a disorder or disease (Parkinson, Attention Deficit Hyperactivity Disorder (ADHD), Alzheimer, diabetes, cardiovascular disorder, respiratory impairments (for example asthma), hypertension, obesity, or any other condition that can impair the lung function), or Raynaud's phenomenon
- Subjects with abnormal diet and sleeping patters and/or abnormal body weight (weight gain or loss >3kg in the past month)
- Subjects who recently participated in other interventional biomedical study within 1 month prior to screening visit
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Temperature and HumidityTemperature and Humidity of room changed | Other | Temperature and Humidity |
Primary outcome
Cognition
Time frame: 1 month
Using a tablet based cognitive test battery
5 secondary outcomes
Heart Rate (bpm)
Time frame: 1 month
Blood pressure (mmHg)
Time frame: 1 month
Metabolic Rate (ml O2//min/kg)
Time frame: 1 month
Skin Temperature (C)
Time frame: 1 month
Body Core Temperature (C)
Time frame: 1 month
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 24 Mar 2025.
- Individual participant dataSharing planned: Yes. If requested raw data will be provided.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Guy Plasqui, PHD principal investigator
Maastricht University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Temperature and Humidity in people with Environmental Exposure and Temperature Change, Body, run by Maastricht University Medical Center at 1 site in Netherlands.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 12 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 24 Mar 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Netherlands. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Cognition (time frame: 1 month). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 24 Mar 2025.