Ways-to-cool-your-room-in-summer, the cheapest and the most efficient way of cooling ones room is by using these: 'vetiver' (chrysopogon zizanioides) mats... they were called as "khus" in hind as per wikipedia... they are popular as 'vetiver' in south india. one of our neighbors used these in summer when i was in my 8th standard.. If you are living in the top floor, the best way is to use a heat reflective coating. i live in bangalore and it gets around 36c during noon and my home used to get too hot. thermometer in my room used to read 1c-2c higher than outside temperature always.