AS HONGKONG'S summer months approach, most people begin to question where can they go to escape the sauna-room humidity that hits the territory. The way to keep cool is to get high. For every 300 metres you rise above sea level, the temperature drops a few degrees. The heat also becomes more dry and, therefore, more comfortable. But you do not have to scale the Alps or the Andes to cool down. There are plenty of cool places within a few hours' flying time from Hongkong. Probably the best known of these is the ''summer capital'' of the Philippines - Baguio. Built by the cool-headed Americans at the turn of the century, Baguio is 2,800 metres up in the pine-forested Sierra Madre mountains. Just a 45-minute flight from steamy Manila, Baguio's pine forests resemble Bavaria's Black Forest more than the tropics. Though devastated by an earthquake in 1990, much of Baguio has been rebuilt, and there is now a score of small hotels where fresh strawberries and mountain honey are offered for breakfast and superb farm-fresh salads make lunch a cool delight. During the day, Baguio is blessedly cool, fresh and invigorating - ideal for golf, tennis and hiking. The Philippines offers another cool getaway which will appeal to the more adventurous. In the highlands of Mindanao island is lovely Lake Lanao and the town of Marawi. The 400-square-kilometre lake is 700 metres above sea level and has air that is cool and clear. As the Muslim capital of the Philippines, there is a distinct Arabic air about Marawi. Local vendors sell attractive brassware with Islamic designs and offer strangers and visitors a sincere ''Peace unto you'' greeting. The only place to stay in Marawi is the simple, yet charming, Marawi Resort Hotel, situated on the beautifully groomed grounds of Mindanao State University. The accommodation is of basic log-cabin design, but the views of Lake Lanao are enchanting and the campus itself is one of the most charming you will find. Most of Malaysia is renown for its intense tropical heat and soggy rain forests. But soon after the British arrived, they set about discovering the best places to find respite from the heat. They built hill stations high in the peninsula's mountains, farfrom the heat of the lowlands. Today, these hill stations still welcome travellers. The Cameron Highlands was discovered in 1885 by the British government surveyor William Cameron, who was delighted by the ''fine plateau shut in by lofty green mountains''. The resort, 1,550 metres above sea level, is a two-hour drive from Kuala Lumpur. Many types of flowers grow in the cool fresh air, as well as tomatoes, grapefruit, lettuce and rhubarb. Vast tea plantations sprawl across the highlands, intersected by waterfalls which spill into the valleys. There's a choice of good hotels for every budget as well as English-style cottages for hire, complete with log fireplaces and fluffy comforters on four-poster beds. The only problem with getting cool is getting reservations. To avoid disappointment, it is best to book at these destinations as soon as you feel that first bead of perspiration on the brow.