We prospectively evaluated afebrile patients admitted to an emergency department (ED), with suspected infection and only tachycardia or tachypnea.The white blood cell count (WBC) was obtained, and patients were considered septic if leukocyte count was >12,000 μL-1 or <4000 μL-1 or with >10% of band forms. Clinical data were collected to examine whether sepsis could be predicted.Seventy patients were included and 37 (52.86%) met sepsis criteria. Self-measured fever showed an odds ratio (OR) of 5.936 (CI95% 1.450-24.295; P = 0.0133) and increased pulse pressure (PP) showed an OR of 1.405 (CI95% 1.004-1.964; P = 0.0471) on multivariate analysis. When vital signs were included in multivariate analysis, the heart rate showed an OR of 2.112 (CI95% 1.400-3.188; P = 0.0004). Self-measured fever and mean arterial pressure <70 mm Hg had high positive likelihood ratios (3.86 and 2.08, respectively). The nomogram for self-measured fever showed an increase of sepsis chance from 53% (pretest) to approximately 80% (post-test).The recognition of self-measured fever, increased PP, and the intensity of heart rate response may improve sepsis recognition in afebrile patients with tachycardia or tachypnea. These results are important for medical assessment of sepsis in remote areas, crowded and low-resourced EDs, and low-income countries, where WBC may not be readily available.