Does the Event Card have to be drawn first when encountering a Town space in A Touch of Evil?
Generally, I would say that since the drawing of the event card is mandatory and the heal action is optional, the drawing of the event card happens first. However, the rules do say: 


  The town of Shadowbrook is divided 
  into a number of spaces.  Each of these 
  spaces allows the Hero to draw an Event 
  card when Encountering the space as well 
  as a special ability that can be used when 
  Encountering the space.


and


  Every other named space 
  has game text printed on the board.  To 
  Encounter any of these spaces, follow the 
  game text listed there.  You will notice that 
  most of the Town spaces also have one or 
  more special abilities which may be used 
  while Encountering the Space (for instance, 
  at the Doctor’s Office you may Heal and 
  /or Cure a Curse in addition to the Draw 
  an Event game text).  These Town space 
  special abilities are always optional.


That kind of sounds like the intent of the special abilities may be to help deal with the event cards drawn during the encounter. If that's the interpretation, I'd rule that you can heal first, but that might be a bit of a stretch. "Encountering the space" seems to mean the entire interaction with the space, not just the event card. 

Since there isn't a definitive answer in anything I can find, I'd go with the rule-of-thumb that mandatory happens before optional.