You know that you can encounter everything from frost in the early morning on the high mountains to a hot midday sun on the coast. Even in San José the nights can be chilly, so bring a sweater or sweatshirt and jacket. Light clothes that can be layered will serve you well.

Costa Ricans dress on the conservative side. Women do wear pants or jeans even in downtown San José, but shorts for men or women are not acceptable except for sports - save them for the beach areas. In a nice restaurants in the evening, most men have on coats and ties or at least a dress shirt; the ladies, dresses.

Cotton and polyester long pants are good. It takes forever and a day for jeans to dry in the rainy season. A long - sleeved shirt or two is wise for protection from sun - remember, rays are direct at ten degrees from the equator - and from insects and scratches on forest trails. Shorts are not recommended for hiking in rain forests.

If you will be staying at hotels or on nature reserves that have shared baths, consider a lightweight sweatsuit for trips to the shower. It can double as sleeping attire if the night is chillier than expected or for something comfortable to change into after a day of sightseeing or travel.

If you stay in the rustic facilities at some parks, you need to bring soap, towel, and sleeping bag or sheets.

When packing your bags, remember that travel to some remote spot by small plane, boat, or jeep may limit what you can take for those few days. Some domestic airlines limit luggage to 26 pounds per person