Indoor cooling or heating devices are usually controlled by adult users rather than children. Preschool children, mostly younger than 6 years, have a small ability to control the thermal environment , and thus they could only rely on the assistance from their guardians to achieve thermal comfort. However, owing to the different thermal perceptions between adults and children, the parents or grandparents may create an inappropriate thermal environment for their children. To quantitatively analyze the differences between adults and preschool children regarding thermal comfort perceptions, a controlled experiment was carried out in a climate chamber. A total of 20 pairs of preschool child and parent participated in the experiment. The children's thermal perceptions are not consistent with those of their parents. The difference is more evident regarding the tolerance to a cool environment than to a warm environment. According to the experimental results, the neutral temperature for preschoolers is 20.1 °C while that for adults is 22.3 °C. The acceptable temperature range for preschoolers is 16.7–23.4 °C, while for adults it is 20.7–23.9 °C. Preschool children have a more robust tolerance to the thermal environment than adults in both subjective and physiological responses. A physical touch on the children's skin could be helpful for the parents to more precisely infer their children's thermal perceptions. • The thermal perception of preschool children and their parents was directly compared in climate chamber. • Two kinds of parents' inferences of children's thermal perceptions were observed and discussed. • The neutral temperature and thermal sensitivity of preschool children are significantly different from their parents. • Preschool children have a more robust tolerance to the thermal environment than their parents.