Temperature Regulation: Hypothermia, Hyperthermia, and Fever

Temperature is one of the most critical variables to your health and survival. We know now that heat and cold exposure have vast effects on our genome (Rhonda Patrick, PhD has done some great reporting that). Hypothermia or hyperthermia can be lethal in a matter of hours or even less.

Your body’s priority in terms of temperature regulation is to provide a stable environment that is optimal for your essential biochemical functions. To do this, it has a few different mechanisms, most of which revolve around water.

Your body uses water as sweat to get rid of heat. Your body also eliminates large amounts of heat via urine. It uses the water you ingest, which is colder than your body temperature, as another means to cool itself. Sweat is also a method the body uses to detoxify itself.

Your body produces heat in every cell as a by-product of your metabolism. The more metabolically active you are, the more heat you produce. Our perceptions of heat also depend on our endocrine systems. We may feel hot, when we are cold, or feel cold, when we are hot. This is why people who are feverish often complain of “chills.” Your hormones, primarily, control your body’s temperature.

I am called about patients with fevers constantly. Everyone wants to bring down a fever, as if curing the symptom is a cure of the disease. Yet a fever is one of your immune system’s strongest tools to bring an infection under control. When fevers are out of control, then it is important to treat them and prevent their damaging the brain or other organs. Usually, the body will regulate a fever on its own, without interference. Recent research suggests that drugs like acetaminophen, which interfere with the body’s temperature management, increase the risk of certain disease in children whose mothers took them while they were in utero.

Just about every decision about where we are, what we wear, and what we do hinges in part on our temperature. If you find yourself outside without a coat on a chilly day, you will stamp your feet and shiver. You will go inside where it is warm, if you can. With climate control in our homes, offices, and cars, there is little time during which we are exposed to the ambient temperature. There are countless variables that have changed as a result. Recirculated air inside our homes and workplaces is higher in air pollutants and allergens than the outside air. Staying indoors to avoid the heat keeps us out of the sunlight. People used to get their exercise just to get out of the heat, whether it was walking to a place to swim or climbing to higher ground where it was cooler. Now, we sit and stew in our recirculated, but perfectly temperature controlled, buildings. This has changed everything about our society, from how we socialize to how we build our communities and cities.

Temperature control is unnatural. Our health has only declined since we made it the norm, rather than the exception. Whether this is due to getting less sunlight, exposure to more air pollutants, changes in socialization, or reductions in our physical activity, we can be sure that constant temperature regulation is something to be wary of. The answer is to bring back healthful pastimes like sauna, to spend more time outdoors, to ditch antiperspirant (though not deodorant, I hasten to add), to ride with the windows down and the AC off, and that’s just to name a few. This isn’t to say that you should throw out your furnace and let your house freeze all winter long, nor that you should get rid of your AC unit and fry during the summer, but be mindful that prior to the modern day, no one lived at 77 degrees Fahrenheit for 24 hours a day and 365 days a year, much less with recirculated air laden with pollutants. There is a reason people enjoy spending time outside, in nature, even if it makes them sweat or shiver. Your environment has changed, that the reasons to get fresh air, sunlight, and to expose yourself to heat or cold are hard-wired into your physiology.