pray-med tells you some common sense about body temperature
While not everyone infected with COVID-19 develops a fever, it remains one of the most common symptoms of the novel coronavirus.
By using a thermometer, you can easily take your temperature; experts even recommend keeping one in your medicine cabinet to monitor for signs of COVID-19. But with so many different types of thermometers to choose from, it can be difficult to decide which one is right for you.
CTVNews.ca spoke with Natalie Crown, a pharmacist at Women's College Hospital and a teaching assistant professor at the University of Toronto's Faculty of Pharmacy, and Dr. Matthew Oughton, an infectious disease specialist at the Jewish General Hospital in Montreal, about some common questions about thermometers and how to use them they.
What is the definition of fever?
The U.S. Centers for Disease Control and Prevention (CDC) considers a fever to be "a temperature measured at or above 100.4 degrees Fahrenheit [38 degrees C]." That being said, the Institute for Public Health acknowledges that this number may vary depending on the type of thermometer used and the age of the person being tested. Generally, it defines a fever as a higher than normal body temperature for a person.
There is much debate about what is a "normal" body temperature for humans. While that figure has long been thought to be around 37°C, or 98.6°F, Harvard Medical School notes, new research suggests that may be an overestimate, and that the average human body temperature is actually around 36.4°C, or 97.5°F.
Ogerton also explained that many factors can affect a person's body temperature, including the time of day. "On average, most people's core temperature will be a little lower around 6 a.m. and a little higher at 6 p.m.," Ogton told CTVNews.ca by phone Monday. "That normal temperature variation can be as much as 0.5 degrees Celsius."
Despite all these influencing factors, and the existing debate about what is "normal," Ogton said: "The CDC's definition of fever is the standard he recommends following. On average, a temperature of 38°C is definitely a symptom of a fever." , I don't think any physician would dispute 38°C as a reasonable indicator of fever."
Do all the thermometers read the same?
According to Crown, not all thermometers are likely to give the same temperature reading, even when used on the same person. Normal body temperature depends in part on where you take your temperature. The main different types of temperature probes include rectal, oral, tympanic (ear), axillary, and temporal (forehead). Given that different parts of the body have slightly different temperatures, for example, thermometers used in the mouth, forehead, and ears will read slightly differently. "A rectal temperature probe is considered the most accurate way to measure body temperature. We generally consider rectal temperature to best reflect the body's true core temperature," Ogerton explains. That's because it gives the best reading from inside the body. Ear thermometers are also thought to offer similar accuracy when measuring temperature.
In addition to these body parts, other parts of the body that are commonly used to measure temperature will give slightly different readings. A person's oral temperature is typically 0.5 degrees Celsius lower than their rectal or ear temperature, according to a medical review by Healthwise, a nonprofit organization that specializes in health education. In addition, a person's armpit and forehead temperatures are usually 0.5 degrees Celsius lower than their oral temperatures. It's important to keep this in mind when taking your temperature to determine if you have a fever, says Ogerton.
Which thermometer is best for home use?
For ordinary families without special needs, Ogton said that he most recommends a digital oral thermometer. This is probably the most useful overall solution and the best balance of costs and benefits overall.
While the wait for results can vary from a few seconds to about a minute, many programs are more convenient to use by beeping or providing other signals that a reading is complete. These thermometers are also available with flexible or rigid tips, depending on the preferred style.
Crown recommends keeping a digital stick thermometer in the home. It can be used in three ways - older children and adults can take their temperature orally, while younger children can take their temperature in the armpits or rectally.
The next best option, says Ogerton, is a forehead thermometer. They're easy to use and one of the most comfortable thermometers on the market. Using an infrared scanner, these devices measure the temperature of the frontotemporal artery.
Like other infrared thermometers, forehead thermometers read temperatures fairly quickly, usually in seconds. Many also emit a signal such as a beep to indicate that the reading is complete. According to the Mayo Clinic, these thermometers are not suitable for use on infants younger than three months. In older children and adults, the temporal artery forehead thermometer is probably one of the most accurate measures of the body's true core temperature. But there is one important downside – price, forehead thermometers are usually more expensive than digital thermometers.
Another slightly cheaper recommendation is a digital ear thermometer. These devices use infrared light to measure temperature, but inside the ear canal they usually record temperature quickly and are reasonably comfortable for both children and adults. According to the Mayo Clinic, digital ear thermometers are only recommended for babies older than 6 months, children, and adults.
Ogerton advises people to be careful of earwax when using these thermometers, as this can affect the accuracy of the measurements. If you have just come in from the outside, it is not recommended to use a digital ear thermometer to take the temperature, because you may get a false low temperature. He recommends waiting about 10 minutes for the temperature in the ear canal to equilibrate with the surrounding environment before taking a temperature with this thermometer.
For infants, Ogton recommends using a rectal thermometer for the most accurate readings. He also recommends that rectal thermometers be clearly labeled and stored in their own compartment.
Crown also recommends that children use an underarm thermometer. A digital stick thermometer placed directly in the middle of your child's armpit is also a good option, although she admits that a rectal thermometer is a more realistic reflection of body temperature. "The really most accurate way to take temperature in children is rectally, but we know it's hard to do, and for most babies and children under five years old - using a stick thermometer in the armpit is actually a Very effective way to measure a child's temperature."
What are the tips for using a thermometer?
In addition to having a working thermometer at home and some extra batteries, Ogton recommends not eating anything before taking your temperature. For example, something extremely hot or cold can affect your temperature reading, depending on the type of thermometer used. "If you want your temperature to be as accurate as possible, you shouldn't put anything in your mouth within 15 minutes of taking your temperature." He also reminded people to make sure to cover the entire sensor or bulb to ensure the most accurate reading.
Finally, Crown recommends that you contact your local pharmacist if you have any specific questions about your thermometer, including what type of thermometer you should be using and how to use it.
Choosing a thermometer can sometimes be confusing. Pharmacists are the most accessible providers of healthcare, and they can advise families on how to interpret their temperature and offer some advice on treating a fever.