Yes, thermal imaging devices can be used both during the day and at night. Thermal imaging technology relies on detecting the heat signatures emitted by objects and living beings, rather than visible light. This means that thermal cameras can operate in total darkness and provide a clear image of the heat differences in their surroundings. During the daytime, thermal imaging devices can still be effective, although the temperature contrasts might not be as pronounced as they are at night. In low-light conditions, such as dawn or dusk, thermal imaging can be particularly useful because the temperature differences between objects and their surroundings are more significant, enhancing the clarity of the thermal image. However, it's important to note that thermal imaging does have its limitations. Factors such as weather conditions (rain, fog, and heavy snow) can affect the accuracy and range of thermal cameras. Additionally, very hot objects might saturate the thermal sensor and appear as white blobs, reducing the details in the image. In summary, thermal imaging devices are versatile tools that can provide valuable insights day and night, with some variations in effectiveness depending on lighting conditions and the specific environment.