Elsevier has created a COVID-19 resource centre with free information in English and Mandarin on the novel coronavirus. The resource centre is hosted on Elsevier Connect, the company's public news and information website. Elsevier grants permission to make all its COVID-19-related research immediately available in PubMed Central and other publicly funded repositories, with rights for unrestricted research re-use and analyses. The article reviews the medical applications of infrared thermography (IRT). IRT is a fast, non-contact, non-invasive method for monitoring body temperature. It can also map body surface temperature remotely. IRT has been successfully used in the diagnosis of breast cancer, diabetes neuropathy, and peripheral vascular disorders. It has also been used to detect problems in gynecology, kidney transplantation, dermatology, heart, neonatal physiology, fever screening, and brain imaging. With modern infrared cameras, data acquisition and processing techniques, real-time high-resolution thermographic images are now possible, which is likely to surge further research in this field. The article discusses the basics of IRT, essential theoretical background, procedures for various measurements, and applications in various medical fields. It provides background information for beginners to better understand the subject. The article also covers experimental conditions for medical IRT, emissivity of human skin, instrumentation (infrared camera and detectors), image processing, data analysis, and numerical modeling. It highlights various medical applications of IRT, including thermoregulation study, breast cancer detection, diagnosis of diabetic neuropathy and vascular disorder, fever screening, dental diagnosis, dermatological applications, blood pressure monitoring, diagnosis of rheumatic diseases, dry eye syndrome, liver diseases, kidney treatment, heart operation, gynecology, and personality testing and brain imaging. The article also discusses the importance of controlled environments in thermography experiments, the role of emissivity in human skin, and the development of infrared cameras and detectors. It covers image processing techniques, data analysis, and numerical modeling in IRT. The article highlights the use of IRT in medical science for various applications, including thermoregulation study, breast cancer detection, diagnosis of diabetic neuropathy and vascular disorder, fever screening, dental diagnosis, dermatological applications, blood pressure monitoring, diagnosis of rheumatic diseases, dry eye syndrome, liver diseases, kidney treatment, heart operation, gynecology, and personality testing and brain imaging. The article concludes with the importance of IRT as an effective alternative diagnosis tool.Elsevier has created a COVID-19 resource centre with free information in English and Mandarin on the novel coronavirus. The resource centre is hosted on Elsevier Connect, the company's public news and information website. Elsevier grants permission to make all its COVID-19-related research immediately available in PubMed Central and other publicly funded repositories, with rights for unrestricted research re-use and analyses. The article reviews the medical applications of infrared thermography (IRT). IRT is a fast, non-contact, non-invasive method for monitoring body temperature. It can also map body surface temperature remotely. IRT has been successfully used in the diagnosis of breast cancer, diabetes neuropathy, and peripheral vascular disorders. It has also been used to detect problems in gynecology, kidney transplantation, dermatology, heart, neonatal physiology, fever screening, and brain imaging. With modern infrared cameras, data acquisition and processing techniques, real-time high-resolution thermographic images are now possible, which is likely to surge further research in this field. The article discusses the basics of IRT, essential theoretical background, procedures for various measurements, and applications in various medical fields. It provides background information for beginners to better understand the subject. The article also covers experimental conditions for medical IRT, emissivity of human skin, instrumentation (infrared camera and detectors), image processing, data analysis, and numerical modeling. It highlights various medical applications of IRT, including thermoregulation study, breast cancer detection, diagnosis of diabetic neuropathy and vascular disorder, fever screening, dental diagnosis, dermatological applications, blood pressure monitoring, diagnosis of rheumatic diseases, dry eye syndrome, liver diseases, kidney treatment, heart operation, gynecology, and personality testing and brain imaging. The article also discusses the importance of controlled environments in thermography experiments, the role of emissivity in human skin, and the development of infrared cameras and detectors. It covers image processing techniques, data analysis, and numerical modeling in IRT. The article highlights the use of IRT in medical science for various applications, including thermoregulation study, breast cancer detection, diagnosis of diabetic neuropathy and vascular disorder, fever screening, dental diagnosis, dermatological applications, blood pressure monitoring, diagnosis of rheumatic diseases, dry eye syndrome, liver diseases, kidney treatment, heart operation, gynecology, and personality testing and brain imaging. The article concludes with the importance of IRT as an effective alternative diagnosis tool.