The restrictions that have been introduced with the Covid-19 pandemic has led to stores having less customers and stores shutting down. There is a need to track people's occupancy in public places so there could be more people in those places but still following the restrictions. This study evaluates and compares three different heat sensors to see if they could be used for this. The three heat sensors that have been used in this study are both low-cost and low-resolution sensors. The choice of low-resolution heat sensors is important to not intrude on people's privacy. In this study, there were three different experiments performed on all the three sensors. The experiments were done to see how sunlight could affect the sensors, what advantages, and disadvantages there are by placing the sensors in different positions, and how good the sensors are at separating people. The collected results gave a good basis to answer the research questions and better understand the sensors chosen in this research. The results also showed that the sensors can be used as an aid against a pandemic when restrictions must be kept. In the discussion we talk about how the sensors performed in different experiments and how they performed against each other. Our chosen method is also discussed and what we think were good and what went wrong so others do not repeat our mistakes. The paper ends with our conclusions and suggestions for future work.