What does Isma do physically when she sees Parvaiz's name on Skype in Chapter One? What does she think of?

Isma puts her hands to her throat and listens to her pulse when she sees Parvaiz's name on Skype. Isma thinks of a few weeks ago hearing the sound of hail hitting icicles and how Parvaiz would have loved to hear the sound. This is the only time Isma has thought of Parvaiz recently without feeling upset.