On a recent trip to visit family in Texas, I got a chance to do a little hiking. Being from an area with a much less humid climate, I got to thinking about the unique issues involved in hiking in high humidity areas. During the Texas spring, wildflowers are in bloom, and some areas of the state are truly a hiker's paradise. But if you're used to dryer weather, you might find that moisture is something of an obstacle. Let's not mince words about it-one of the most difficult things about hiking in humidity is the sweat. I'll admit that Texas Hill Country has lower humidity than some places I could have chosen, but by the end of the day, I was feeling very, very swampy. Do yourself a favor and bring along a towel or old T-shirt to keep yourself dry. I would also recommend that you carefully think about what type of fabric you're wearing before you go. Not only are some fabrics, like denim, more absorbent than others, not all clothes are equally friendly to the skin when you've been out in the sun all day. I'll spare you the detail, but let's just say that I would not recommend denim. My hiking partner wore a pair of lightweight, moisture-wicking pants, and I wish I had done the same. An issue related to perspiration is hydration. Some people think that you do not actually produce more sweat in humid climate, but the slower evaporation makes it seem like you do. This is a myth. In fact, most people do perspire more in humid climate. The reason is this - it's true that sweat takes longer to evaporate in humidity, and evaporation is the primary reason that perspiration cools us down. When our sweat evaporates, heat goes with it, and the air can reach our damp skin to decrease our body temperature. In humid weather, the lack of evaporation means that sweating is a less efficient way of cooling off, so you produce more sweat to make up for the reduced efficiency. So what does all this mean for hydration? It's simple - bring extra water. You'll be sweating more, and all that moisture has to come from somewhere! Make sure you pack enough water to replenish yourself. Since your body has a harder time cooling itself down in humid climate, take extra precautions to make sure you'll be cool enough. Dressing lightly is one good way to stay cool, but remember that snakes, plants, and insects can be dangerous to bare skin. Wearing a hat is essential in humid climate, to keep cool, and storing water out of the sun inside a pack can help keep it cold. Most of all, check the weather in advance, and don't plan a long hike for an exceptionally humid day. It is important to distinguish between humidity and altitude, but the two are not totally unrelated. At high altitude, the air pressure is lower than it is at sea level. This means that, the air is thinner and can't hold as much water. That's why higher altitudes tend to be dryer, while low altitudes are more humid. Of course, there are exceptions to this rule. For example, dense but dry air is often found in deserts at low altitudes. In general, though, if you are in a climate that's more humid than you're used to, chances are good that the altitude is also lower than you're used to. Hiking at low altitude is different from altitude hiking, because the denser air can deliver more oxygen to your body. This might make the hike feel easy to you, but remember not to overdo it! With a little advance preparation, hiking in humid weather can be a wonderful experience. If you've thought about the unique aspects of humidity hiking ahead of time, you are sure to have a good hike.