This research is intended to evaluate the use of the infusing thinking skills technique in teaching Form Four Physics in the topic of heat through the students’ achievements in the Critical Heat Test. The research involves the types of thinking skills, which are the parts-whole relationships, comparing and contrasting, and conceptualization. Teachers need to choose the most suitable type of thinking skills for the topic that will be taught in order to attain the learning outcome required. Additionally the infusing thinking skills technique, along with thinking skills, also contain the training of mind of habits in the behavior of students and metacognition whereby students will reflect on the thinking skills process during the teaching and learning activity. The use of thinking maps according to the type of thinking as mentioned, can help students think in step by step sequence. The methodology of the study is quasi-experimental and shows the disproportionate test design of the pre- and post-test groups. Research samples are purposive sampling, containing 30 people for each treatment group and control group. Two schools in Kinta Utara were involved in this study. Results show that there are significant differences in test-t, that is the score increment (critical heat posttest score-pretest score) of the treatment group as compared to the control group. It is found that the infusing thinking skills technique is suitable to enhance thinking skills and the students understanding of the heat topic. This technique is an alternative for teachers to apply various types of thinking skills required in Physics to train thinking skills to the students. Through conceptualization skills, students will be able to find Physics concepts from what they already know and from their daily experiences by using conceptual maps.