Warm weather is often accompanied by high humidity. It is the most common adverse environmental factor encountered by athletes. Gradual adjustment to unaccustomed heat is made through living in warmer condition as well as training. The athlete takes 10 to 20 days of heat acclimatization. The heat and humidity will increase body's production of sweat. Therefore, all heat training requires a careful attention of hydration. On the other hand, cold weather may be accompanied by snow. It requires the layered clothing protection. It can also present hydration problem as energy generated in the activity and fluid lost to perspiration is less apparent but equally impacts the body
