A History of Temperature Measurements

Chapter 1 in the upcoming book

I'm excited to share the first chapter of my upcoming book on hypothermia and temperature management! While I may tweak a few things before it’s finalized, I’d love to hear your thoughts and feedback. Just a heads up, the full preview of each chapter is available to paid subscribers only, but free subscribers can enjoy a sneak peek at the beginning of each chapter. Stay tuned for more chapters dropping in the upcoming months! Chapter 1 is the history of temperature measurement. The next chapter will be basic temperature physiology.

Chapter 1: A History of Temperature Measurement

Understanding temperature and how it is measured is fundamental to modern medicine. As a prehospital provider, you are likely well familiar with the thermometer, but the tools and understanding we have today, developed over many centuries. This chapter will guide you through that evolution, from early qualitative assessments to today's sophisticated devices.

Early Concepts of Fever

The idea of fever as a sign of illness has been around since ancient times. Hippocrates, often called the "father of medicine," wrote about febrile diseases with marvelously precise descriptions, noting the characteristic temperature fluctuations in diseases like malaria and pneumonia. However, these early observations were made without the aid of thermometers. Instead, physicians used cutaneous palpation (touching the skin) to determine if a patient was feverish.

Galen, a Roman physician, further contributed to early thermometry by establishing a concept of a neutral temperature using a mixture of boiling water and ice. He then proposed four degrees of heat and four degrees of cold, using the effects of pharmaceutical agents on patients to assign a qualitative level of heat or cold.

These early ideas were based on qualitative assessment rather than quantitative measurement. Though not exact, these observations laid the groundwork for later advancements.

The First Thermometers

The creation of true temperature-measuring devices occurred much later. The first known thermometer-like instrument was the air thermometer, detailed by Philo of Byzantium in the first century CE. This device operated by using the expansion of air in a bulb to displace water in a graduated stem, which gave a relative measurement of temperature temperature.