A reusable temperature sensing probe assembly comprises a temperature sensor strip extending from one end of a handle. The temperature sensor strip carries at least one temperature sensor for measuring temperature within a body cavity of a person, such as the rectum. The handle/temperature sensor strip is reversibly positionable within a unitary balloon/sleeve assembly comprised of a balloon portion and a sleeve portion. The balloon portion is comprised of a first interior space configured to hold the temperature sensor stip and a second interior space separate from the first interior space that is configured for inflation. An inflation tube has one portion sealed within the second interior space of the balloon portion and a second portion which extends through the sleeve portion for connection to a fluid source.