Images of ice appear at various points in the story, symbolizing fear, dread, and the feeling of being unsettled or shocked. For example, when the narrator first reads about Sonny's arrest, he describes the feeling as follows:
A great block of ice got settled in my belly and kept melting there slowly all day long. . .. It was a special kind of ice. It kept melting, sending trickles of ice water all up and down my veins, but it never got less. (2)
The narrator can't escape this icy feeling, which returns as "icy dread" (77) when Sonny first gets to his apartment after getting out of jail. We often think of ice (and cold) as causing discomfort, and this is precisely what happens when (figurative) ice appears in "Sonny's Blues."