Staying properly hydrated will help keep you feeling energized, try drinking at least eight 240 mL (8 oz.) glasses of water a day. If you do get sick, try to drink continuously throughout the day. Water is essential to help your body fight illness.

Your body excretes water constantly through sweat, urine and exhaled air, which is why it's so important to replenish your body throughout your day. Your body will tell you when you need more. When you're even mildly dehydrated you'll feel thirsty and you may even have dry mouth or dry lips.

Other symptoms of dehydration are divided into moderate and severe categories.

Moderate dehydration symptoms:

  • Lack of skin elasticity
  • Sunken eyes

Severe dehydration symptoms:

  • All of the above symptoms
  • A rapid, weak pulse
  • Cold extremities
  • Rapid breathing
  • Confusion
  • Lethargy

Dehydration can be the result of forgetting to drink enough water and vomiting and diarrhea, as well as overexposure to the sun and fever. Diuretics and natural diuretics such as alcohol and caffeine can also cause dehydration. So, be sure to drink large amounts of water when you're ill or enjoying the great outdoors.