In one aspect the present invention provides a door strike which prevents the opening of an associated door when the door strike has been heated to an elevated temperature of at least about 1000° F., preferably when the door strike is at higher temperatures such as are present during a fire in a building structure. The door strike includes a thermally responsive element which retards the normal operation of the door strike when it is at an elevated temperature. A further aspect of the invention is a method for controlling the undesired spread of a fire or smoke between adjacent spaces separated by the door wherein a fire or smoke condition exists in at least one of these spaces, via the provision of a door strike having a thermally responsive element which retards the normal operation of the door strike when it is at an elevated temperature.