The Effects of Daytime, Nighttime, and Combined Heat Exposure on Human Health

NCT07501923 | Recruiting

• 1 other identifier: 81250681
• Study Type: interventional
• Target: 35
• Locations: 1 country
• Sites: 1

Brief Summary

Assess the acute effects of high-temperature exposure (including both daytime and nighttime conditions) on multiple physiological and psychological indicators, including cardiovascular, respiratory, neuropsychiatric, and metabolic functions, along with their potential mechanisms.

Conditions

Metabolism Changes; Psychology Functional Behavior; Cardiovascular System; Respiratory System

Outcome Measures

Primary Outcomes (11)

• Heart Rate Variability

  Smart Band will be conducted during each exposure session. Time-domain and frequency-domain HRV indices (e.g., SDNN, RMSSD, LF, HF) will be derived to assess autonomic nervous system regulation.

  Volunteers will be asked to wear smart band for 24 hours from 6:00 A.M. at the day of intervention to 6:00 A.M. at the next day.

• Systolic and Diastolic Blood Pressure

  Blood pressure will be measured using an automated sphygmomanometer under standardized resting conditions. Both systolic and diastolic values will be recorded.

  Blood pressure will be examined before exposure and immediately (within 10 mins) after the exposure session

• Forced Expiratory Volume in 1 Second

  Pulmonary function will be assessed using spirometry according to standardized protocols. FEV1 will be recorded as a measure of airway function.

  Lung function will be examined before exposure and half an hour after the exposure session

• Forced Vital Capacity

  Forced vital capacity will be measured via spirometry to evaluate lung volume and ventilatory function.

  Lung function will be examined before exposure and half an hour after the exposure session

• Interleukin-6

  Venous blood samples will be collected and serum IL-6 concentrations will be quantified using enzyme-linked immunosorbent assay (ELISA) to assess systemic inflammatory response.

  Blood will be collected 1 hour before and after the exposure session

• C-reactive Protein

  Serum CRP levels will be measured using high-sensitivity assays as a marker of systemic inflammation.

  Blood will be collected 1 hour before and after the exposure session

• F2-Isoprostanes

  Plasma or urinary F2-isoprostanes will be quantified using validated assays as a stable biomarker of lipid peroxidation and oxidative stress.

  Blood will be collected 1 hour before and after the exposure session

• Superoxide Dismutase

  Serum SOD activity will be measured to evaluate antioxidant defense capacity.

  Blood will be collected 1 hour before and after the exposure session

• Serum Creatinine

  Serum creatinine will be measured using standard biochemical methods to assess renal function.

  Blood will be collected 1 hour before and after the exposure session

• Urinary Neutrophil Gelatinase-Associated Lipocalin

  Urinary NGAL levels will be quantified using ELISA as an early biomarker of acute kidney injury.

  Urine will be collected 1 hour before and after the exposure session

• Profile of Mood States

  Psychological status will be assessed using the validated POMS questionnaire to evaluate mood disturbances.

  Scale assessments will be conducted within one hour before and after exposure.

Secondary Outcomes (7)

• Heart Rate

  Volunteers will be asked to wear smart band for 24 hours from 6:00 A.M. at the day of intervention to 6:00 A.M. at the next day.

• Peak Expiratory Flow

  Lung function will be examined before exposure and half an hour after the exposure session

• Tumor Necrosis Factor-alpha

  Blood will be collected 1 hour before and after the exposure session

• Monocyte Chemoattractant Protein-1

  Blood will be collected 1 hour before and after the exposure session

• Glutathione

  Blood will be collected 1 hour before and after the exposure session

Study Arms (2)

Intervention / Treatment

OTHER

Daytime or Nighttime High-Temperature Group

Other: Daytime or Nighttime High-Temperature Exposure

Control

OTHER

Daytime or Nighttime Neutral -Temperature Group

Other: Daytime and nighttime neutral temperature exposure

Interventions

Daytime or Nighttime High-Temperature Exposure OTHER

Daytime Exposure Phase: The exposure group will be exposed to high temperature (32#) in a chamber for about 8 hours, resting during the whole periods Nighttime Exposure Phase: The exposure group will be exposed to high temperature (30#) in a chamber for about 8 hours, resting during the whole periods Day-Night Combined Exposure Phase: The exposure group will be exposed continuously to high temperatures during the day and night

Intervention / Treatment

Daytime and nighttime neutral temperature exposure OTHER

Daytime Exposure Phase: The control group will be exposed to neutraltemperature (26#) in a chamber for about 8 hours, resting during the whole periods Nighttime Exposure Phase: The control group will be exposed to neutral temperature (26#) in a chamber for about 8 hours, resting during the whole periods Day-Night Combined Exposure Phase: The control group will be exposed continuously to neutraltemperatures during the day and night

Control

Eligibility Criteria

• Age: 18 Years - 30 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Age 18-30;
• In good health, with no history of cardiovascular disease, respiratory disease, diabetes, endocrine disorders, neurological or psychiatric conditions;
• No smoking or alcohol addiction, no history of substance abuse;
• No prior history of particular sensitivity to high-temperature environments.

You may not qualify if:

• Individuals who have experienced fever, colds, infectious diseases, or significant physical trauma within two weeks prior to the high-temperature test;
• Individuals currently using medications that may affect psychological, cognitive, cardiovascular, or respiratory functions;
• Pregnant women and lactating females;
• Participants shall not be scheduled to participate during menstruation;
• Individuals with a history of fainting or severe discomfort caused by high temperatures.

Sponsors & Collaborators

• Jian Cheng: lead

Study Sites (1)

Anhui Medical University

Hefei, Anhui, 230032, China

RECRUITING

Central Study Contacts

Jian Jian Cheng

CONTACT

+86 183 5603 7837; jiancheng@ahmu.edu.cn

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Professor

Study Record Dates

• First Submitted: March 18, 2026
• First Posted: March 30, 2026
• Study Start: June 1, 2025
• Primary Completion (Estimated): September 30, 2026
• Study Completion (Estimated): December 31, 2026
• Last Updated: March 30, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)