That physical quality generally referred to as hotness or coldness that results from the vibration of kinetic energy in our bodies. We measure this energy/temperature with devices called thermometers using the scales of either Celsius (°C) or Fahrenheit (°F). Many digital thermometers come with options to switch between Celsius and Fahrenheit, but if you need to manually switch the conversion formulas are;
°F = (°C * 9 / 5) + 32
°C = (°F - 32) x 5 / 9
Be familiar with the thermometer your team uses and follow the directions it comes with. Also, remember to keep spare batteries on hand. Inside the body the hypothalamus regulates the body temperature, which should normally be 36.2 to 37.5°C (97.2 to 99.5°F). While many factors affect body temperature there are 2 general categories to consider, how much the body generates heat either by activity or fever, and how much the environment affects the body either by absorbing heat or giving heat to the body. Realize that a lot can happen with the body and temperature, from shunting blood, to releasing sweat, to funneling blood to an infection. Just because the patient’s hand feels cool does not mean they do not have a fever.
While internal medicine doctors may consider gut (gastrointestinal) thermometers the gold standard of temperature measurement, for lay people assisting with first aid and EMS we use simple less invasive options.
| Ages Group | Ages Range | Systolic or Upper Number (mmHg) | Diastolic or Lower Number (mmHg) |
|---|---|---|---|
| Newborn | 0-1 months | 60-90 | 20-60 |
| Infant | 1-12 months | 87-105 | 53-66 |
| Toddlers | 1-3 years | 95-105 | 53-66 |
| Children | 3-12 years | 95-112 | 56-71 |
| Adolescents | 12-18 years | 112-128 | 66-80 |
| Adults | 19 years & above | 90-120 | 60-80 |
We listed some commonly accepted core body temperatures of awake adults below. Ranges vary by age group, method for taking the temperature, and activity.
Note that current research considers that there may be a new normal body temperature of 36.4 or 36.6 °C (97.5 or 97.9 °F), as this research is ongoing. Always remember to assess the patient, not just the device.
Thank you to _____ for help with the photographs. Heroism takes teamwork.
References
Cleveland Clinic. (2023, March 15). Vital Signs. Retrieved from Cleveland Clinic: my.clevelandclinic.org/health/articles/10881-vital-signs
Dolibog P, P. B. (2022, February 9). Comparative Analysis of Human Body Temperatures Measured with Noncontact and Contact Thermometers. Healthcare (Basel, Switzerland).
LeWine, H. E. (2023, May 22). Fever in adults: When to worry. Retrieved from Harvard Health Publishing: www.health.harvard.edu/diseases-and-conditions/treating-fever-in-adults
Limmer, D. O. (2007). Emergency Care 10th Ed. Upper Saddle River, New Jersey: Pearson Education Inc.
Obermeyer Z, S. J. (December 2017). Individual Differences in Normal Body Temperature: Longitudinal Big Data Analysis of Patient Records. The BMJ. Sapra A, M. A. (2023, May 1). Vital Sign Assessment. StatPearls.
Sund-Levander M, F. C. (2002, June). Normal Oral, Rectal, Tympanic and Axillary Body Temperature in Adult Men and Women: a Systematic Literature Review. The Scandinavian Journal of Caring Sciences.