If you're a person who doesn't burn in the temperate zone and want to know what a sunburn feels like, don't follow this advice. Sunglasses are also recommended. Although very few tourists have been bitten by poisonous snakes in Costa Rica, they do exist in the areas to which you will be traveling. Without becoming paranoid, a few precautions are advisable. Consider all snake poisonous unless your guide tells you otherwise.
Small snakes can be just as deadly as big snakes.
Rather than step over onto the blind side of a log or rock that is obstructing the trail, step on top of it and look before you step down. The soil and leaf litter on the forest floor is generally a random pattern. They are, however, usually coiled before they strike. In the back of your mind connect round with danger. While a snake bite is not a common accident, falling down is.