An optimal two-bout strategy with phase change material cooling vests to improve comfort in hot environment

The results of the parametric study showed that heat storage is reduced in the second bout due to wearing the second vest with lower PCM melting temperature, thus thermal comfort and sensation are significantly improved. The optimal case at the 40 °C environment uses a vest with 21 °C PCMs in the first bout and a vest with 21 °C PCMs in the second bout (V21→V21). At 45 °C, the optimal case is V18→V10 with significant PCM weight reductions from the reference single bout case by a minimum of 47%. Thus, the issue of extra carried weight that affect metabolism and ease of movement when applying continuous cooling during work have been mitigated by using the two-bout strategy.