Every day, emergency departments and acute medical units all over the world receive and assess thousands of patients. Most are stable, but a few require immediate stabilization. To identify these, all patients are routinely triaged and have vital signs measured. Our group has shown that thermographic images of the face can be an alternative method for identifying patients at increased risk of 30-day mortality. In our previous studies, the thermographic images were taken after the patients had been inside for at least 30 minutes. However, to identify patients at risk, the images have to be available as quickly as triage, i.e. at the door when the patient arrives. Therefore, we have performed a small study, with the aim of illustrating the effect of such heat-gradients on thermal images of the face.