Effects of Environmental Heat Exposure on Human Multiple Organ Function

Exposure to Environmental Heat and Intervention Study

This is a randomized controlled human exposure crossover study. Investigators aims to assess the acute effects of high temperature exposure and the underlying mechanisms.

Study Overview

• Status: Completed
• Conditions: Wounds and Injuries; Body Temperature Changes; Heat Stress Disorders; Multiple Organ Dysfunction
• Intervention / Treatment: Other: High temperature exposure; Other: Moderate temperature exposure

Detailed Description

The objective of this study is to study changes in functions of multiple organs under heat exposure, which mainly include changes of cardiac function and lung function. In addition, biological samples such as blood samples, nasal fluid, and urine, etc were collected to explore changes in biomarkers such as complete blood count, liver function, kidney function, and inflammatory indicators, etc. Biochemical analysis and omics analysis were conducted to study the changes of human physiological function caused by heat exposure.

• Study Type: Interventional
• Enrollment (Actual): 27
• Phase: Not Applicable

Contacts and Locations

Study Locations

• China
  • Shandong
    • Jinan, Shandong, China
      • Shandong University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

1. Chinese nationality（aged 18-30 years healthy males and females）;
2. With ability to read and understand Chinese smoothly;
3. Living in Jinan during the study period;
4. Body mass index ≥ 18.5 and ≤ 28;
5. Normal resting ECG；
6. Normal lung function: i. Forced vital capacity (FVC)≥80% of that predicted for gender, ethnicity, age and height; ii. Forced expiratory volume in one second (FEV1) ≥80% of that predicted for gender, ethnicity, age and height; iii. FEV1/FVC ratio≥80% of predicted values.

Exclusion Criteria:

1. Medications or dietary supplements intake that may alter body temperature during the study period;
2. Individuals who have unspecified illnesses, which in the judgment of the investigators might increase the risk associated with heat exposure will be a basis for exclusion;
3. Subjects with anemia, needle fainting and other signs unsuitable for blood drawing；
4. Subjects with cardiovascular diseases or other chronic medical condition, such as congenital heart disease, pulmonary heart disease, and hypertension, etc;
5. Subjects with a history of major cardio-vascular, respiratory, or nervous system surgery, etc;
6. Subjects with neurologic disorders, such as stroke, traumatic brain injury, epilepsy, and depression;
7. Subjects with allergic diseases, such as allergic rhinitis and allergic asthma, etc;
8. Subjects are pregnant, attempting to become pregnant or breastfeeding;
9. Subjects who are currently smoking (including vaping, hookah and e-cigarette) or have smoking history within 1 year of study (defined as more than 1 pk/yr in the past year) or have a greater than equal to a 5 pack year smoking history;
10. Subjects living with a smoker who smokes inside the house;
11. Subjects who are current drinking or have frequent alcohol use (defined as at least 1 time per week) in the past 6 months;
12. Provisional exclusion criteria, such as acute infection in the past two weeks or taking antibiotics. (Subjects can be enrolled after 2 weeks)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: High temperature group; This group including 24 healthy subjects will be exposed to high temperature for about 3 hours in a chamber.	Other: High temperature exposure; Subjects will be exposed to 35 degree Celsius and 45% relative humidity for 3 hours, resting during the whole periods.
Sham Comparator: Moderate temperature group; This group including 24 healthy subjects will be exposed to moderate temperature for about 3 hours in a chamber.	Other: Moderate temperature exposure; Subjects will be exposed to 24degree Celsius and 45% relative humidity for 3 hours, resting during the whole periods.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Systolic and diastolic blood pressure	Brachial arterial blood pressure will be measured	Systolic and diastolic blood pressure will be measured within 15 minutes before exposure and immediately after the exposure session, and every 15 minutes during exposure.
Cardiac output	Cardiac output will be measured by heart color ultrasound	Cardiac output will be checked within half an hour before exposure and immediately after exposure.
Heart rate variability	Heart rate variability will be measured using 24-hour holter electrocardiogram	Cardiac variability will be monitored in real time from half an hour before exposure to half an hour after exposure, with data automatically recorded every 8 seconds.
Change of forced expired volume in the first second (FEV1)	The changes of FEV1 will be measured by a smart spirometer. Before the pulmonary function test, subjects will practice several times by themselves. During the examination, each subject stands and clamps the nose clip, and repeats the test, with the best result as the criterion.	FEV1 will be checked within half an hour before exposure and 15 minutes after exposure.
Changes of forced vital capacity (FVC)	The changes of FVC will be measured by a smart spirometer.	FVC will be checked within half an hour before exposure and 15 minutes after exposure.
Changes of peak expiratory flow rate (PEF)	The changes of PEF will be measured by a smart spirometer.	PEF will be checked within half an hour before exposure and 15 minutes after exposure.
Changes of maximum expiratory flow rate at 25% vital capacity (MEF25)	The changes of MEF25 will be measured by a smart spirometer.	MEF25 will be checked within half an hour before exposure and 15 minutes after exposure.
Changes of maximum expiratory flow rate at 50% vital capacity (MEF50)	The changes of MEF50 will be measured by a smart spirometer.	MEF50 will be checked within half an hour before exposure and 15 minutes after exposure.
Changes of maximum expiratory flow rate at 75% vital capacity (MEF75)	The changes of MEF75 will be measured by a smart spirometer.	MEF75 will be checked within half an hour before exposure and 15 minutes after exposure.
Inflammatory factors and antioxidant-related biomarkers in nasal cavity fluid	Inflammatory factors were detected by the ELASA	Collect nasal fluid samples half an hour before exposure and half an hour after exposure

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Differences in metabolic profiling detected in blood between the two exposures and before and after each exposure	The differential metabolic profiling in peripheral blood related to high temperature exposure will be detected by mass spectrometry-based non-targeted metabolomics.	Prior to and 1 hour after exposure
Differences in transcriptome detected in blood between the two exposures and before and after each exposure	The differential transcriptome in peripheral blood related to high temperature exposure will be detected by mass spectrometry-based non-targeted transcriptomics.	Prior to and 1 hour after exposure
Differences in proteome detected in blood between the two exposures and before and after each exposure	The differentially expressed proteins in peripheral blood related to high temperature exposure will be detected by non-targeted proteomics	Prior to and 1 hour after exposure
EEG power in α band	EEG power in α band will be monitored by EEG measuring instrument	EEG power in α band will be measured immediately during the same exposure period the day before exposure and within half an hour of the end of the exposure day.
EEG power in θ band	EEG power in θ band will be monitored by EEG measuring instrument	EEG power in θ band will be measured immediately during the same exposure period the day before exposure and within half an hour of the end of the exposure day.
EEG power in β band	EEG power in β band will be monitored by EEG measuring instrument	EEG power in β band will be measured immediately during the same exposure period the day before exposure and within half an hour of the end of the exposure day.
EEG power in δ band	EEG power in δ band will be monitored by EEG measuring instrument	EEG power in δ band will be measured immediately during the same exposure period the day before exposure and within half an hour of the end of the exposure day.
Response event-related potentials (ERPs)	ERPs will be monitored by EEG measuring instrument, including P300, N1/P1 and so on.	ERPs will be measured immediately during the same exposure period the day before exposure and within half an hour of the end of the exposure day.
Frequency domain and energy ratio index, θ/β ratio	θ/β ratio will be monitored by EEG measuring instrument, which is an important parameter for response frequency domain and energy ratio index	θ/β ratio will be measured immediately during the same exposure period the day before exposure and within half an hour of the end of the exposure day.
Cerebral blood flow changes	Cerebral blood flow changes will be measured by transcranial doppler	Cerebral blood flow changes will be examed within half an hour before exposure and half an hour after exposure.
Differences in proteomics detected in nasal fluid between the two exposures and before and after each exposure	Collect nasal fluid samples for proteomics analysis	Prior to and 1 hour after exposure

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in tumor necrosis factor-α (TNF-α) concentrations	TNF-α will be tested through blood samples	Prior to and 1 hour after exposure
Change in C reactive protein (CRP) concentrations	CRP will be tested through blood samples	Prior to and 1 hour after exposure
Change in interleukin-6 (IL-6) concentrations	IL-6 will be tested through blood samples	Prior to and 1 hour after exposure
Change in interleukin-1β (IL-1β) concentrations	IL-1β will be tested through blood samples	Prior to and 1 hour after exposure
Change in liver function indicators	Liver function indexes will be tested through blood samples, including glutamic-pyruvic transaminase (ALT), glutamic oxalacetic transaminase (AST), glutamyltranspeptidase (GGT), alkaline phosphatase (ALP), total protein (TP), albumin(ALB), total bilirubin (TBIL), direct bilirubin (DBIL) and so on.	Prior to and 1 hour after exposure
Change in kidney function indicators	Liver function indexes will be tested through blood samples, including urea nitrogen (BUN), creatinine (CR), Cystatin C (CYS C) and so on.	Prior to and 1 hour after exposure
Change in Uric Acid (UA)	UA will be tested through blood samples	Prior to and 1 hour after exposure
Change in myocardial and vascular injury indicators	myocardial and vascular injury indicators will be tested through blood samples, including creatine kinase (CK), Creatine Kinase Isoenzyme (CKMB), lactic dehydrogenase (LDH), α-hydroxybutyrate kinase and so on.	Prior to and 1 hour after exposure
Change in coagulation indicators	Coagulation indicators will be tested through prothrombin time(PT), activated partial thromboplastin time (APTT), plasma fibrinogen (FIB), thrombin time (TT) and so on.	Prior to and 1 hour after exposure
Blood routine examination	A routine test in the blood test, including red blood cells, white blood cells, platelets and other aspects of the test.	Prior to and 1 hour after exposure
Routine urianlysis	A routine test in the urine sample, including urine specific gravity and so on.	Prior to and 1 hour after exposure
Change in D-lactic acid	D-lactic acid will be tested through blood samples	Prior to and 1 hour after exposure
Change in diamine oxidase(DAO)	DAO will be tested through blood samples	Prior to and 1 hour after exposure
Weight	Weight will be measured using a scale, wearing only short-sleeved shorts and slippers	Prior to exposure and immediately after the exposure session

Collaborators and Investigators

• Sponsor: Yinan Qu
• Collaborators: Qilu Hospital of Shandong University

Study record dates

Study Major Dates

• Study Start (Actual): May 21, 2025
• Primary Completion (Actual): May 31, 2025
• Study Completion (Actual): June 30, 2025

Study Registration Dates

• First Submitted: April 4, 2025
• First Submitted That Met QC Criteria: April 14, 2025
• First Posted (Actual): April 22, 2025

Study Record Updates

• Last Update Posted (Actual): May 14, 2026
• Last Update Submitted That Met QC Criteria: May 11, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Wounds and Injuries; Heat Stress Disorders; Body Temperature Changes
• Other Study ID Numbers: LL20241102

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No