Complex sentence: The Bruneian public has been advised by authorities to drink plenty of water and seek medical treatment if their condition were worsen while being warned against any open burning and other actions that may worsen the conditions.
Split into simpler sentences: The Bruneian public has been advised by authorities to drink plenty of water and seek medical treatment if their condition worsens. Authorities have also warned against any open burning and other actions that may worsen the conditions.