<p>We investigated the correlations between the net baryon number and electric charge up to the sixth order related to the interactions of nuclear matter at low temperature and explored their relationship with the nuclear liquid–gas phase transition (LGPT) within the framework of the nonlinear Walecka model. The calculations showed that strong correlations between the baryon number and electric charge existed near the LGPT, and higher-order correlations were more sensitive than the lower-order correlations near the phase transition. However, in the high-temperature region away from the LGPT, the rescaled lower-order correlations were relatively larger than most of the higher-order correlations. In addition, some of the fifth- and sixth-order correlations possibly changed sign from negative to positive along the chemical freeze-out line with decreasing temperature. In combination with future experimental projects at lower collision energies, the derived results can be used to study the phase structure of strongly interacting matter and analyze the related experimental signals.</p>