If you need to be seen by a Doctor, we recommend Hospiten Playacar. Very close to the condo on the highway just south of Sams Club. English speaking personnel and very high standards. There is good information here regarding insurance, 911 etc. Check with your health insurance beforehand to see what coverage you may have while traveling in Mexico
Yesterday, I published an article for tourists about the different medical treatment options in Mexico called Visiting Mexico: What to Do If You Get Sick or Injured. The timing of that article coincided with my own trip to the doctor yesterday.