  We investigate the 3rd term of spectral heat content for killed subordinate
and subordinate killed Brownian motions on a bounded open interval D = (a, b)
in a real line when the underlying subordinators are stable subordinators with
index \alpha is in (1, 2) or \alpha = 1. We prove that in the 3rd term of
spectral heat content, one can observe the length b-a of the interval D.
