Heat exhaustion and heat stroke are serious problems when the mercury starts to climb.It's easy to underestimate how dangerous heat sickness can be. A few common sense precautions can make the difference between life and death.Drink a lot of liquidsIt is easy to get dehydrated in hot climates, especially if you are not used to high temperatures. Always carry a water bottle and drink from it often. Just because you aren't thirsty doesn't mean your body doesn't want water; by the time you feel thirsty, you are already a little dehydrated. A good rule of thumb is: if you aren't visiting the restroom as often as you would normally, you aren't getting enough water.Lay off the booze and coffeeAlcohol and caffeine promote dehydration. You need two cups of non-caffeinated and non-alcoholic beverages for every cup of coffee, tea, beer, etc. that you consume just to break even.Salt helpsIf you don't have a health reason to avoid them, eat salty snacks such as olives and pickles throughout the day. The salt will help you retain some of the extra fluids you're consuming.Potassium aplentyPeople who are sweating more than usual may be losing electrolytes, which can cause headaches and other symptoms. If you find yourself feeling headachy, try replacing your electrolytes with a sport beverage or a high-potassium snack such as a banana.Pack lots of sunblockThere are few better ways to ruin a vacation than a painful sunburn. Make the application of sunscreen or sunblock a part of your morning routine, and reapply regularly.Cover upKeep your head covered with a light-colored hat or scarf. By keeping your head and the nape of your neck covered, you can help avoid sunstroke.Seek the shadeNo matter how much sunblock you use or how wide your hat is, you can still overheat easily just sitting in direct sunlight. Whenever possible, walk, stand, or sit in the shade.Pace yourselfAvoid heat exhaustion by pacing yourself and taking it easy. Most people don't realize they are overexerting themselves just by sticking to their usual activity level while exposed to temperatures they are unaccustomed to.Take a high-noon hiatusAvoid the midday sun. This is the time of the day when the sun's rays are at their highest intensity, and the maximum skin damage can occur; plan traveling and sightseeing for the early morning or evening.Go naturalAvoid wearing synthetic fibers that do not allow your skin to breathe. Wear natural fabrics like cotton or linen that are absorbent and allow air through. Rayon, while it tends to be lightweight and cottony in appearance, tends to trap heat next to your skin. Additionally, opt for light-colored clothes over darker ones that tend to absorb heat rather than reflect it.Be good to your feetTake at least two pairs of shoes so that you can let each pair dry out on alternate days. Sandals are not advised due to the threat of insect bites, sunburn, stubbed toes, and blisters.Love the A-CTry to stay in air-conditioned hotels and use air-conditioned vehicles.If you find yourself experiencing symptoms such as dry, flushed skin, difficulty breathing, and/or dizziness, faintness, or light-headedness, immediately seek relief from the heat: get into some shade, preferably in an air-conditioned room; sit or lie down quietly; put a rag dipped in cool water or wrapped around a piece of ice against your wrists and the back of your neck; and generally get yourself cooled off as soon as possible.If symptoms persist or worsen, seek immediate medical assistance.