# Convert Fahrenheit (°F) & Celsius (°C)

## Convert to Fahrenheit

$\frac{T×9}{5}+32$
• T = Celsius

$\frac{\left(T-32\right)×5}{9}$
• T = Fahrenheit

## Examples

1. Convert 37°C to Fahrenheit.

$\frac{\mathrm{37}×9}{5}+32$

2. Convert 98.6°F to Celsius.

$\frac{\left(98.6-32\right)×5}{9}$

## Medical Relevance

Core temperature
The temperature of the deep tissues of the body—the “core” of the body—remains almost exactly constant, within ±1°F (±0.6°C), day in and day out except when a person febrile illness.
Normal core temperature
The average normal core temperature is generally considered to be between 98.0° and 98.6°F when measured orally and about 1°F higher when measured rectally.
Hyperpyrexia
Occurs between 105—108°F. Circulatory shock, cell destruction and organ failure are followed by death.
Hypothermia
Occurs between 94—77°F. Once the core temperature falls below 85°F temperature regulation is lost. Death by cardiac arrest or ventricular fibrillation occurs once body temperature falls to 77°F.

## Temperature Assessment Sites

• Pulmonary artery (most accurate)
• Esophageal
• Rectal
• Tympanic
• Oral
• Axillary
Reference temperatures
Rectal Oral Tympanic Axillary
37.5 37 36.8 36.4
99.5 98.6 98.2 97.6
Actual average temperatures collected in three clinical studies. Population sizes 7,636, 1,000 and 433.
37.04 36.64 36.57 35.97 35.09
98.67 97.95 97.82 96.74 95.16

## References

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• Hall, J. E., & Hall, M. E. (2020). Guyton and Hall textbook of medical physiology e-Book. Elsevier Health Sciences.
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• Geneva, I. I., Cuzzo, B., Fazili, T., & Javaid, W. (2019, April). Normal body temperature: a systematic review. In Open Forum Infectious Diseases (Vol. 6, No. 4, p. ofz032). US: Oxford University Press.
• Ng, D. K. K., Chan, C. H., Chan, E. Y. T., Kwok, K. L., Chow, P. Y., Lau, W. F., & Ho, J. C. S. (2005). A brief report on the normal range of forehead temperature as determined by noncontact, handheld, infrared thermometer. American journal of infection control, 33(4), 227-229.
• Coran, A. G., Caldamone, A., Adzick, N. S., Krummel, T. M., Laberge, J. M., & Shamberger, R. (2012). Pediatric surgery E-book (Vol. 2). Elsevier Health Sciences.
• Robinson, J. L., Seal, R. F., Spady, D. W., & Joffres, M. R. (1998). Comparison of esophageal, rectal, axillary, bladder, tympanic, and pulmonary artery temperatures in children. The Journal of pediatrics, 133(4), 553-556.