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

Condition(s) studied

Investigational drug(s) / intervention(s)

Daytime or Nighttime High-Temperature Exposure: 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

Daytime and nighttime neutral temperature exposure: 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

Study 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.

Eligibility

Primary outcome measure(s)

• Heart Rate Variability — 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.
  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.
• Systolic and Diastolic Blood Pressure — Blood pressure will be examined before exposure and immediately (within 10 mins) after the exposure session
  Blood pressure will be measured using an automated sphygmomanometer under standardized resting conditions. Both systolic and diastolic values will be recorded.
• Forced Expiratory Volume in 1 Second — Lung function will be examined before exposure and half an hour after the exposure session
  Pulmonary function will be assessed using spirometry according to standardized protocols. FEV1 will be recorded as a measure of airway function.
• Forced Vital Capacity — Lung function will be examined before exposure and half an hour after the exposure session
  Forced vital capacity will be measured via spirometry to evaluate lung volume and ventilatory function.
• Interleukin-6 — Blood will be collected 1 hour before and after the exposure session
  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.
• C-reactive Protein — Blood will be collected 1 hour before and after the exposure session
  Serum CRP levels will be measured using high-sensitivity assays as a marker of systemic inflammation.
• F2-Isoprostanes — Blood will be collected 1 hour before and after the exposure session
  Plasma or urinary F2-isoprostanes will be quantified using validated assays as a stable biomarker of lipid peroxidation and oxidative stress.
• Superoxide Dismutase — Blood will be collected 1 hour before and after the exposure session
  Serum SOD activity will be measured to evaluate antioxidant defense capacity.
• Serum Creatinine — Blood will be collected 1 hour before and after the exposure session
  Serum creatinine will be measured using standard biochemical methods to assess renal function.
• Urinary Neutrophil Gelatinase-Associated Lipocalin — Urine will be collected 1 hour before and after the exposure session
  Urinary NGAL levels will be quantified using ELISA as an early biomarker of acute kidney injury.
• Profile of Mood States — Scale assessments will be conducted within one hour before and after exposure.
  Psychological status will be assessed using the validated POMS questionnaire to evaluate mood disturbances.

Trial sites (1)

Other trials for the same condition