Nowadays, in several countries in the tropical islands of Indian Ocean including Madagascar island, Comores island, Seychelles island and Mayotte, no adapted and regulated buildings standards exist. This entails enormous losses for their government, a great urban disorder, and facilitates the anarchic constructions. The human health depends essentially on the internal climate. Several actions should be taken to propose solutions to this problem. The purpose of this research is to develop a database on thermal comfort in naturally ventilated buildings in order to improve indoor air, mainly in hospitals and shopping centers in the largest island of the Indian Ocean. There is not enough data regarding comfort in built environments in this region. Experimental and subjective results of field study carried out in 5 big hospitals and 50 small and big shopping centers, distributed in 25 districts of urban areas in Northern Madagascar are presented. The adaptive approach was adapted for this purpose.A specific questionnaire was elaborated for the investigation according to ISO 7730 and 10551. A total, of 400 people were investigated during rainy and dry seasons. This paper discusses the influence of gender, clothing, activities, voters' mind state and occupants' control strategies on adaptive comfort assessment and various comfort parameters calculated for these buildings. In both studied places, the lower and upper acceptable temperature for 80% of the voters were 23.2°C and 26.8°C, while the 90% of the customers and patients reported a comfortable temperature range of 24.5°C-26.2°C. This will help to define guide lines for constructing more comfortable buildings in Madagascar and other countries on the Indian Ocean.