Under elevated temperature conditions, Yemeni honey bees exhibited better thermal tolerance than hybrid Carniolan honey bees. Variations between body characteristics, cuticular lipids, cuticle thickness, and total body water content of the two races were investigated. Yemeni bees were smaller than Carniolan bees in all measured body characteristics. The cuticle thickness of Carniolan bees was significantly higher than that of Yemeni honey bees. The cuticular lipid profiles of the two races were similar, and there were no significant differences in the total body water content between them. The results of this study highlight that body size plays a central role in the high thermal tolerance of Yemeni bees over that of Carniolan bees. However, further investigations are required to understand the variations between the two races.