Always wear comfortable footwear with good gripping soles when walking around the rim. Sun protection, light loose clothing will help keep you cool in the warmer months. In the winter, a jacket or other covering will shield you from the wind. Always bring more water than you think you will need. The dryness of the desert will sneak up on you, especially if you are traveling from somewhere with more moisture in the air. During the hotter months having drinks or food with electrolytes to replenish the salt your body loses while sweating is highly recommended.