803(3) Then-Existing Mental, Emotional, or Physical Condition = state of mind (i.e. motive, intent, plan) or emotional, sensory, or physical condition (i.e. mental feeling, pain, bodily health). Ex: "I'm hungry," "I'm so nervous I'm dripping sweat," "I plan to fly to Denver tomorrow." (Merritt p. 525)
But NOT incl. a statement of memory or belief to prove the fact remembered or believed UNLESS it relates to the validity or term of declarant's will. Ex: "I remember how hot I felt yesterday" admissible to show declarant remembered the feeling at the time statement made, but not to prove that declarant felt that way. (Merritt p. 528)
More reliable than other hearsay b/c reduced risk of memory/perception issues. (Merritt p. 526) Statements reflect declarant's own internal feelings in the moment. Internal states admissible; external events/conditions inadmissible. (Merritt p. 529)