What can i do if a burn blister exploded?

Use antibiotic cream: Apply antibiotic cream and a protective dressing.

Avoid infection: If it is opened and fluid has come out, put pressure to express the remaining fluid and to create flat contact with the top layer of skin; it will act as a covering. Put some antibiotic creme (bacitracin, neosporin etc) on it and cover with a band aid and keep it clean. Look for signs of infection, and if needed see md.

See a doctor: He can check for infection and order an antibiotic cream called silvadene (silver sulfadiazine) which is usually used in these situations.