Sunny and near 75°.
Does that sound like your kind of forecast? Me too!
It just feels perfect. So that brings us to the pressing question. What is considered the ideal temperature? Science tells us that there may be an exact answer, and while there are many factors involved, 75° ain’t far off!
THE HUMAN BODY
Our core body temperature is around 98°. It’s a high number because there’s a lot going on underneath the skin. Organs are working, food is being digested, and muscles are operating with precision. All of this takes energy which is then released in the form of heat. That heat is then purged through our body by expelling that energy into the surrounding air. Evaporation of sweat is also used to regulate our body temperature. If the air around us were also 98°, then we’d actually be very uncomfortable. Our bodies couldn’t expel the heat! It turns out that scientists have determined that 70° is close to ideal for allowing that heat to disperse properly. This explains why days like today are just so nice!
HUMIDITY AND OTHER FACTORS
Temperatures aren’t the only deciding factor, however. Humidity plays a huge role in all of this. The more humidity, the harder it is to release heat. Lack of breeze cuts down on evaporation and therefore heat removal, as well. This is why you’ll hear meteorologists talk about heat index and wind chill factors (a slightly different process) because they are important. That’s also why an air conditioner’s role of removing humidity is just as important as regulating the temperature.
So, we know what’s most comfortable, but what are our limits? According to a study in the journal Science Advances, a wet-bulb temperature of 95° is the highest temperature people can endure. What’s a wet-bulb temperature you ask? The wet-bulb temperature is measured by a thermometer covered in a water-soaked cloth, allowing it to take into account heat and humidity. So, a 95° wet-bulb temperature would essentially translate to a day well into the 100s, with very high humidity (a rarity across the world). It wouldn’t allow us to regulate our bodies.
On the flip side, extreme cold is damaging, too. While an exact number for cold is slightly more nebulous — depending on the length of exposure and what’s around you — when your body temperature falls below 95°, hypothermia sets in. Generally, a body temperature below 70° will result in death. Technically, this can occur when the air temperature drops below 40°.
So, what is the rule for inside your air-conditioned house? The same rules apply, but keep in mind that air conditioners regulate humidity. So, with that in mind, the World Health Organization says the ideal range is between 64° and 75°. It goes on to recommend that the minimum temperature be kept above 68° for the very young, elderly, or sick. Most of us in South Texas have learned to keep the numbers a bit higher to allow for the conservation of energy.