If you find the summer's heat unbearable, consider one of these cooling getaways:

* Skiing in Chile: It's winter south of the Equator, and Portillo, the Chilean resort in the Andes, rates as one of the world's great off-season places to ski. A one-week all-inclusive trip in July (air fare, lodging, meals, ski-lift tickets) is about $1,750 per person (double occupancy) via LanChile, Chile's national airline.

* Strolling in San Francisco: When the fog rolls in, the City by the Bay can get downright chilly, and on many a summer evening you are likely to need a sweater or jacket. A 30-day advance-purchase round-trip ticket from Washington on most airlines is $258.

* Sailing in Glacier Bay: Take one of the summer cruise ships to Alaska; they sail right up to the glaciers. A seven-day round-trip from Vancouver, British Columbia, to Glacier Bay aboard Princess Cruises ranges from $1,337 to $2,000 per person.

* Sightseeing in Iceland: The landscape is fascinating, and moderate temperatures put a bounce into your step. A 21-day advance-purcease round-trip fare from Baltimore/Washington International on Icelandair is $639 midweek for a seven- to 90-day stay.

* Camping in the High Sierras: The days are warm, but when the California sun drops behind the mountains you will reach for your winter parka. Yosemite, Kings Canyon and Sequoia national parks offer drive-in campgrounds and primitive wilderness campsites in superbly scenic country.

* Exploring the ice caves of Austria: Among the many cool caves open to the public, the largest is the Eisriesenwelt, south of Salzburg. A guided tour takes you to an immense domed cavern called, descriptively, the Ice Palace.

* White-water rafting almost anywhere: The sun may be hot, but the cold water splashing your face cools you instantly. Class VI River Runners of Lansing, W. Va., one of this region's many outfitters, offers a four-day ride down the New River for $285 per person (meals and rafting).