India is country of festivals, social aggregations with organized actions for specific purposes. Stories are framed for every festival. Realities of stories in same forms may be matter of investigation, but the idea behind the symbolic representation is pure scientific if original forms mentioned with texts are taken. Holi is similar festival celebrated in India (more in North Indian states) with lots of zestfulness. Slight variations in programs are observed with regional input in different states, but story as whole remains same related with Haranyakashyapa, his sister Holika and his son Prahlad. His son was follower of Lord Vishnu, who nurtures the world. Holika tried to burn Prahlad, a symbolic representation of good deeds or carriers of goods being the devotee of Lord Vishnu. Holika herself burnt down to ash in process. Here Holika is symbolic representation of bad. Medically, bad comes to different diseases, carriers of microorganisms or pathogens.
Riveting to process, in western UP, camphor, cardamom, clove, betel, ghee etc. are added in Holika dahan. Timing of Holi indicates seasonal mutation from winter to spring, where killing of microorganisms are essential as optimum temperature for growth is supposed to approaching. Camphor, cardamom and clove are proved antimicrobials and compounds spread through smoke to environment.
Very next day morning, festival of Holi is celebrated with colours (rang and gulal). Traditionally these colours were byproducts of plants with medicinal values as leaves of gulmohar, spinach etc. for green colours; turmeric for yellow colours; pomegranates, red sandal, palash, hibiscus etc. for red; indigo, grapes etc. for blue; beetroot for purple; catechu and other tannins for brown; amla etc. for black. Conventionally people used to oleation before going for colours. Oil works as vehicle for compounds to be absorbed as well as it helps in maintaining moisture too. All the way enthusiasm, singing, dancing etc. are symbolism for physical works after chilled winter. Close observation with scientific understanding may leave scientific clues for different other festivals too celebrated in India.