With the proper location and allocation of emergency medical centers, the mortality rate of emergency patients could be improved by providing the required treatment within an appropriate time. This paper deals with the location design of emergency medical centers in a given region under the closest assignment rule. It is assumed that the capability and capacity to treat various categories of treatable medical diseases are provided for each candidate medical center as a function of possible subsidies provided by the government. It is further assumed that the number of patients occurring at each patient group node during a unit time is known along with the categories of their diseases. Additionally, to emphasize the importance of timely treatment, we use the concept of a survival rate dependent on patient transportation time as well as the category of disease. With the objective of minimizing the total subsidies paid, we select from among the candidate medical centers subject to minimum desired survival rate constraints.