Phase change cooling garments (PCCGs) utilize phase change materials to store and release thermal energy, which can be used to reduce thermal sensation in hot environments. This study aims to investigate the effects of PCCGs on thermal comfort and electroencephalography (EEG) signals for laborers in hot conditions. Experiments were conducted in a climate chamber at 33 °C with 50% relative humidity, with subjects having a metabolic rate of 2.7 met. EEG signals from 20 participants were recorded using a 32-channel EEG system after completing laboring task wearing the PCCGs or normal garment (NG), and the mean power of EEG and topological features of the brain network were analyzed. The results indicate that the use of PCCGs significantly reduce the mean power of the EEG signals, with notable changes in the θ, α, and β-bands. Additionally, wearing PCCGs alters the topological structure of the brain network, and the inter-regional information exchange was enhanced, as evidenced by the increased clustering coefficient, global efficiency, local efficiency, and decreased characteristic path length of the brain network. In this study, the effects of PCCGs on thermal comfort, EEG activity and brain network of laborers in hot environment were explored, which provides a possible indicator for assessing the improvement of thermal comfort by PCCGs.