Fever is an increase in body temperature. Cases of mild fever are often beneficial because they represent the body's defense mechanism against infection. Many pathogenic microorganisms proliferate in narrow temperature ranges, so a low fever prevents them from reproducing. In some cases, however, fever can be linked to connective tissue diseases or neoplasms. High fever (above 39.5 ° C for adults) is potentially dangerous and should be checked often with a thermometer. There are many types and models of thermometers, specific to different areas of the body. The best choice is determined by the age of the patient with the fever; for example, some thermometers are more suitable for small children. When you've found the best tool, using it is pretty straightforward.
Steps
Part 1 of 2: Choosing the Best Thermometer
Step 1. Use a rectal thermometer for infants
The best means of measuring fever mostly depends on the patient's age. For babies up to six months of age, the recommended method is to use a regular digital thermometer to measure rectal (anal) temperature, because it is considered the most accurate.
- Wax in the ears, infections and small curved ear canals interfere with the accuracy of ear thermometers which, for these reasons, are not the most suitable for newborns.
- Some research suggests that thermometers that measure temporal artery temperature are viable alternatives, due to their accuracy and reproducibility of the result. You can find the temporal artery in the temple region on the head.
- The American Academy of Pediatrics does not recommend the use of older mercury thermometers. Glass can break and mercury is toxic to people, so digital thermometers are safer options.
Step 2. Choose carefully where to take a small child's temperature
For children up to five years of age, rectal measurement of body temperature, performed with a digital thermometer, is still considered the most accurate. You can use an ear thermometer even on young children to get general measurements (better than lack of information), but up to about three years old, measurements in the rectum, armpits, and near the temporal artery are considered more accurate. Since cases of mild to medium-intensity fever can be more dangerous for children than for adults, it is especially important to get accurate measurements at a young age.
- Ear infections are common and occur regularly in infants and young children. The inflammations they cause interfere with the measurement made by the infrared ear thermometer. Consequently, the temperatures measured with this instrument are often higher than the real ones.
- Regular digital thermometers are quite versatile and can measure the temperature under the tongue, in the armpits or in the rectum, and are suitable for babies, toddlers, young people and adults.
Step 3. Choose a thermometer and measure the temperature of older children and adults at any point
After five years of age, children develop fewer ear infections and it is much easier to clean them to remove excess wax. The wax in the ear canal prevents a correct temperature measurement because the infrared signal does not bounce off the eardrum. Additionally, children's ear canals grow and become straighter over time; consequently, beyond the age of five, all types of thermometers, used in all areas of the body, offer similar results in terms of accuracy.
- Digital ear thermometers are often considered the easiest and fastest way to measure body temperature.
- Using a normal digital thermometer rectally is very accurate, but it is undoubtedly the most unpleasant and laborious method.
- Forehead heat-sensitive strips are convenient and inexpensive, but they aren't as accurate as digital thermometers.
- There are some "forehead" thermometers that do not use plastic strips. They are more expensive, are usually used in hospitals and use infrared technology to obtain measurements in the temporal zone.
Part 2 of 2: Using the Different Thermometers
Step 1. Use an oral digital thermometer
Measurement from the mouth is considered a reliable representation of body temperature if the thermometer is inserted deep under the tongue. To use this method of measurement, take the digital thermometer and turn it on; slip the metal tip into a new disposable plastic cap (if available); insert it carefully deep under the tongue; gently close your lips around the thermometer until you hear the "beep". This may take a few minutes, so breathe through your nose while you wait.
- If you don't have a disposable cap, clean the tip of the probe with warm soapy water (or alcohol), then rinse with cold water.
- Wait for 20-30 minutes after smoking, eating or drinking cold or hot liquids before taking a fever by mouth.
- People's body temperature averages 37 ° C (although it can vary depending on many factors), but oral temperatures measured with a digital thermometer have a tendency to be slightly lower, averaging 36.8 ° C.
Step 2. Use a digital thermometer rectally
The rectal measurement is usually reserved for infants and young children, but it is also a very accurate method for adults, although of course it is rather unpleasant. Before inserting a digital thermometer into the anus, be sure to lubricate it with petroleum jelly. Lubricant should usually be applied over the probe cap to aid insertion and reduce discomfort. Separate the buttocks (the procedure is easier if the patient is lying on his stomach) and insert the tip of the thermometer no more than 1.5 cm into the rectum. Never push if you encounter resistance. Wait for the beep for about a minute, then slowly remove the thermometer.
- Be especially careful when washing your hands and the thermometer after a rectal measurement, as E. coli bacteria found in stool can cause serious infections.
- For rectal measurements, flexible tip digital thermometers are best suited.
- Rectal measurements may be one degree higher than those taken in the mouth and in the armpits.
Step 3. Use a digital thermometer under your arms
The armpit area is another point where temperature can be measured, although it is not considered as accurate as the mouth, rectum or ear (eardrum membrane). After covering the thermometer probe with the plastic cap, make sure the armpit is dry before inserting the meter. Hold the tool in the center of your armpit (pointed upwards, towards your head), then bring your arm close to your body to keep the heat from dissipating. Wait a few minutes before you hear the "beep".
- Wait at least an hour after strenuous exercise or a warm bath before taking your body temperature.
- For greater accuracy, measure the temperature under both armpits and average the two readings.
- Axillary digital thermometer measurements have a tendency to be lower than those taken elsewhere, averaging 36.5 ° C.
Step 4. Use an ear thermometer
These instruments have a different shape from regular digital thermometers, because they are specifically designed to enter the ear canal. They measure infrared (heat) rays reflected from the eardrum. Before you begin, make sure your ear canal is wax-free and dry. Accumulations of wax and other residues in the canal reduce the accuracy of the measurement. After turning on the thermometer and attaching the sterile cap to the tip, hold your head still and pull the top of the pinna back to stretch the canal and facilitate insertion of the instrument. It is not necessary to touch the eardrum with the tip, because the instrument is designed to measure the signal from a distance. Press the thermometer against the ear canal to make it adhere to the skin, then wait for the "beep" that communicates the success of the operation.
- The safest and most effective way to clean your ears is to use a few warm drops of olive oil, almond oil, mineral oil or special ear drops to soften the wax, then rinse everything off with water sprinkled by a small specific rubber tool for cleaning the ears. It is easier to clean them after a shower or bath.
- Don't use an ear thermometer if you have infections, injuries, or are recovering from surgery in that area.
- The advantage of the ear thermometer is that its measurements are quick and quite accurate if used correctly.
- Ear thermometers are more expensive than regular digital instruments, but their price has dropped a lot over the past decade.
Step 5. Use a plastic strip thermometer
These instruments are held against the forehead and are quite common for measuring the temperature of babies, although they are not always accurate. They use liquid crystals that react to heat by changing color to indicate the temperature of the skin, but not that of the body. They are usually applied horizontally to the forehead for at least a minute before being checked. Before using them, make sure your skin is not sweaty or sunburned; these conditions affect the measurement.
- It is difficult to measure tenths of a degree with this method, because liquid crystals change color over a range of temperatures.
- For greater accuracy, apply the strip closest to the temple (above the temporal artery near the hair). The blood in the temporal artery is more similar to the internal body temperature.
Step 6. Learn to interpret the measurements
Remember that infants have lower body temperatures than adults - generally below 36.1 ° C, compared to 37 ° C for an adult. Therefore, a measurement that indicates low fever for an adult (37.8 ° C for example), may be of more concern for an infant or young child. In addition, the various types of thermometers measure different average temperatures because they are used in specific parts of the body. For example, your child has a fever if: the rectal or ear measurement is 38 ° C or more, the oral measurement is 37.8 ° C or more, the axillary measurement is 37.2 ° C or more.
- In general, call your doctor if: your baby (3 months or younger) has a rectal temperature of 38 ° C or higher; your baby (3 to 6 months of age) has a rectal or ear temperature that exceeds 38.9 ° C; your baby (6 to 24 months) has a temperature that exceeds 38.9 ° C with any thermometer for more than a day.
- Almost all healthy adults can tolerate high fever (39-40 ° C) for short periods without having any problems. However, if the temperature reaches 41-43 ° C (a condition known as hyperpyrexia), medical attention is needed. Temperatures above 43 ° C are almost always fatal.
Advice
- Read the thermometer instructions carefully. While almost all digital thermometers work the same way, you need to make sure you are using your specific instrument perfectly.
- Prepare the thermometer for measurement by pressing the power button; make sure the reading is zero before applying the disposable plastic cover over the probe tip.
- You can buy disposable plastic caps at the drugstore. They don't cost much and are often universal in size.
- Babies do not regulate their body temperature well when they are sick and may become cold rather than hot and feverish.
- Wait 15 minutes before taking your temperature if you've been drinking something cold or hot.
Warnings
- An ear temperature of 38 ° C or higher is considered a fever, but if your child is over one year old, drinks lots of fluids, plays games, and sleeps normally, there is usually no need for urgent medical attention.
- Temperatures that exceed 38.9 ° C, in combination with symptoms such as irritability, discomfort, lethargy, cough of medium or severe intensity and diarrhea require a visit to the doctor.
- Symptoms of high fever (39.4-41.1 ° C) often include hallucinations, confusion, severe irritability, and seizures; are considered medical emergencies and you should seek treatment immediately.
