Please check your daily newspaper for current exchange rates, as these are sometimes subject to strong fluctuations. In Turkey, Euros are accepted almost anywhere. Swiss francs only in larger stores. Under normal circumstances, it is recommended to exchange money in Turkey and only small amounts.
If you just require"ordinary" medical care, INSURANCE CARDS/PAPERS will NOT BE ACCEPTED. If necessary, you would need to have your paper certified at your respective Consulate (Istanbul or Ankara). Generally, you would pay medical bills in cash and receive an invoice from the doctor. Upon return, you submit the invoice to your health insurance.
The best option is to purchase tickets and the use public telephones.
Changing between Greece an Turkey is possible, but only with the written consent of the base management.
INFORM YOURSELF DIRECTLY AT THE BASE.