"Traveling Well: A Comprehensive Guide to Your Health Abroad," by W. Scott Harkonen, M.D. Dodd, Mead. 286 pp. $11.95 paperback.

A case of malaria, the unwelcome souvenir of an extended trip to Africa, focused author Scott Harkonen's attention on the potential hazards of travel abroad. He had, he admits, been a bit "cocky" when he set out for a year's travel in 1978 without any worries about falling ill.

A medical student at the time of the trip, he has since devoted part of his studies to the health problems of travelers. Now doing research in immunology at the University of California at San Francisco, he frequently is consulted on questions of travel medicine.

His book is quite comprehensive. It details ways to prevent or treat common travelers' ailments (jet lag, diarrhea, blisters, mountain sickness); provides a helpful look at the health hazards and vaccination requirements of countries from Afghanistan to Zimbabwe; and explains the various kinds of health insurance available for travelers.

He urges travelers to seriously consider obtaining medical evacuation insurance, and describes policies on the market. The cost of transporting a seriously injured traveler home, he says, can run into the tens of thousands of dollars.

There is also a chapter for people with special health problems, including kidney and lung disease. "Thanks to modern transportation, concerned organizations and the desire to get out and see the world," he writes, "travel is possible for nearly everyone, regardless of health or disability."

He has, he says, tried to avoid sounding "too negative" because he doesn't want to frighten people from visiting developing countries. Forewarned, however, they should have a better chance of returning home healthy.

* "Rocky Mountains and the Great Plains," a Sierra Club Guide to the National Parks. Random House. 272 pp. $12.95 paperback.

This is the third in a projected five-part series of attractive new guidebooks to the nation's 48 national parks.

The seven parks in the latest volume are: Yellowstone and Grand Teton in Wyoming; Glacier in Montana; Badlands and Wind Cave in South Dakota; Theodore Roosevelt in North Dakota; and Rocky Mountain in Colorado.

The series thus far, including the latest book, provides an excellent introduction to the parks. The books combine superb color photography with concise but thorough outlines of each park's history and geology and extensive guides to its most-significant features.

Travelers heading west might plan a stop in North Dakota once they have read the chapter on Roosevelt park, which takes in 70,000 acres of badlands on the Little Missouri River, stretches of upland prairie as well as a large portion of the former president's ranch lands.

But, explains the book, "the park protects more than grasslands; it preserves the experience that transformed T.R. Its bustling prairie-dog towns, skies graced with soaring eagles and great herds of grazers give it the feel of the African plains, where humans share the landscape with many creatures -- their equals."

Recreational activities for each park are listed; hiking trails are described; and a full-color appendix displays the plants and animals you might be expected to see on a visit.

NOTE: National park fans might also be interested in "The Complete Guide to America's National Parks" (Viking, 327 pp., $7.95 paperback). A state-by-state reference to all the nation's 360 national park areas, it includes historic sites, preserves, monuments, national seashores and other categories of parklands. It is the "Official Visitors Guide" of the National Park Foundation.

OF LOCAL INTEREST:

* "Country Adventures in Maryland, Virginia & West Virginia," by Elizabeth C. Mooney (Washington Book Trading Company, 158 pp. $5.95 paperback): A guide to 38 one-day or weekend vacations within 150 miles of Washington. Here you find "some of the loveliest countryside anywhere in America," writes the author. Her goal has been to seek out "places where the feel of the country survives . . . " Dining and lodging recommendations are included.

* "A Pocket Guide to Maryland's Chesapeake Bay," by Howard A. Chatterton (Nautical & Aviation Publishing Company, 46 pp., $4.95): Don't expect comprehensive looks at the Chesapeake Bay's quaint historic communities. Instead, this is a thin but handy reference for watching the passing scene, binoculars at your eyes. Illustrations clearly point out the different types of sailing vessels -- from sailboard to ocean-going freighter and military ship -- to be seen on the bay. Also: Guides to identifying freighters serving Baltimore, the most-common waterfowl and the fish you might catch.