Using protective or combat garments under heavy heat stress conditions, during rest or exertion, may hinder the body's ability to effectively exchange heat with the environment and thereby can lead to heat injuries. The purpose of this research is to physiologically examine the new textile solutions that are planned to be integrated in the protective garments, combat garments and work uniforms in the army, by evaluating the physiological stress obtained during exertion under hot climatic conditions.

10 young, healthy civilian volunteers will participate in this study. After reading and signing an informed consent form, all subjects will undergo medical examination which includes ECG, anthropometric measurements and Vo2max test. Afterwards, the subjects will perform 6 acclimatization days carried out by the standard protocol of Heat Tolerance Test (HTT). After acclimatization, the subjects will undergo 4 experiment days under heavy heat stress in a climatic chamber, dressed in each experiment day with one out of 4 clothing combinations (NBC protective garment [charcoal base], combat garment and 2 different types of work uniforms). Physiological stress will be evaluated from rectal temperature and heart rate measurements.

Inclusion Criteria:

• Aged 18-30 years.
• Healthy civilian volunteers.
• Without known medical illness or medication use.

Exclusion Criteria:

• The existence or suspicion of existing cardiac or respiratory disease.
• Hypertension.
• Diabetes.
• Psychiatric condition.
• Any muscles or skeledon condition.
• Any hormonal disease or any other chronic illness that may inhibit participation in the experiment.
• Infectious disease 3 days prior to the experiment.