We have seen it many times and even experienced it ourselves in our initial visits to Bali, getting sick or injured with no insurance.  As you are in a foreign country on holidays no one likes to think that they may get sick or injured but this is a fact of life and does happen.  Generally we are changing climates, will eat food that is cooked in different oils then we may use at home, drink more alcohol then normal, so even if it is something as small as an upset stomach you may require some type of medical assistance and if you do not want to be returning to work to pay off your holiday, then pay the small fee for medical insurance as when you compare the medical bills that don’t take long to rack up you will see that the insurance fee is really not that high.  Should you be unfortunate and get sick or become injured then remember to tell your treating physician any allergies or reactions to medication you may have.