Objective To compare the effects of yeast, lipopolysaccharide (LPS), and 2,4-dinitrophenol on fever and respiratory functions in mice by a real-time temperature monitoring technique. Methods Twelve SPF C57BL/6J female mice were implanted intraperitoneally with animal core body temperature monitoring capsules. The mice were randomly divided into blank control, yeast, LPS, and 2,4-dinitrophenol groups by their body weight and temperature. After injection of the corresponding heating medium, body weight was recorded every day, and the recording frequency of the animal core body temperature monitoring capsule was times 15 min. Three days later, non-invasive respiratory monitoring was performed in mice, and specific airway resistance (sRaw), tidal volume (TV), respiratory rate (F), and airway conductivity (sGaw) were measured. At the end of the experiment, the mice were dissected, their thymus, spleen, and lungs were weighed, and organ indexes were calculated. Results During the experiment, body weight of the blank control group continued to increase, body weight in yeast and 2,4-dinitrophenol groups continued to decrease, and body weight in the LPS group increased within 48 h and decreased after 48 h. There was a hightly significant difference in the spleen index between normal and yeast groups (P<0. 01), and there were significant differences in thymus index between normal and yeast groups, and between normal and 2,4-dinitrophenol groups (P<0. 05). Body temperature in the yeast group began to increase at 3 h after injection, remained high within 48 h, and reached the maximum during 24 ~ 48 h, which was statistically different from that in the blank control group (P<0. 01). From 48 to 72 h, body temperature in the yeast group began to decrease gradually, and there was no statistical difference between yeast and blank control groups (P>0. 05). Body temperature in the LPS group increased at 4 h after injection and decreased at 8 h after injection, but it remained higher than that in the blank control group. Non-invasive respiratory monitoring showed that sRaw in yeast, LPS, and 2,4-dinitrophenol groups was increased, while TV, F, and sGaw were decreased. Conclusions From comparisons of the febrile duration, yeast as the heating medium caused the longest febrile duration, followed by LPS and 2,4-dinitrophenol. By comparing fever trends, yeast induced a state of first decreasing and then increasing temperature, reaching the peak at 10 h after injection, LPS induce a state of continuous warming, reaching the peak at 4 h after injection, and 2,4-dinitrophenol induced a state of first decreasing and then increasing temperature, reaching the peak at 8 h. From the comparison of respiratory functions, mice injected with the heating medium showed increased airway resistance, an inhibited respiratory rate, reduced tidal volume, and weakened airway conduction. By comparing the effects of the three heating media on respiration, yeast had strongest effects on the respiratory rate, tidal volume, airway resistance, and airway conduction. Therefore, yeast has a more significant effect on the duration and peak of fever and inhibits respiratory functions.