Roughly 20%–30% of elderly persons with serious bacterial or viral infections will present with a blunted or entirely absent fever response [2, 3, 15]. In the old, bacteremia [16, 17], endocarditis [18, 19], pneumonia [20, 21], and meningitis  may present with lower fever than in the young.
The immune system doesn’t function as efficiently in older adults as it does in younger people. The body’s fever response to infection is not always automatic in elderly people. More than 20 percent of adults over age 65 who have serious bacterial infections do not have fevers.
Fevers without a known cause are relatively common among younger adults. But among seniors, fevers are more likely to indicate a serious viral or bacterial infection. They can also be the result of heat stress, sepsis, malignant growths, medication side-effects, or a symptom of common chronic conditions like arthritis.
Adults. Among adults, the average body temperature ranges from 97°F (36.1°C) to 99°F (37.2°C). Adults over age 65. In older adults, the average body temperature is lower than 98.6°F (37°C).
For an older person, a body temperature of 95°F or lower can cause many health problems, such as a heart attack, kidney problems, liver damage, or worse. Being outside in the cold, or even being in a very cold house, can lead to hypothermia. 4
A fever may be the first or only sign of infection. But some infections may not present with fever and it could be another symptom. Contact your 24 hour advice line immediately if you’ve had cancer treatment recently and think you might have an infection.
It’s possible to feel feverish but not have a fever, and there are many possible causes. Certain underlying medical conditions may increase your intolerance to heat, while some medications you take can also be to blame. Other causes may be temporary, such as exercising in the heat.
Urinary tract infections, or UTIs, are the most common bacterial infection in older adults, reports the AAFP. The use of catheters or the presence of diabetes can increase the risk of UTIs in elderly people.
Seek medical attention if a senior’s fever reaches 103 F (39.4 C) or higher. Get immediate medical help if the fever is accompanied by: Headache. Disorientation or confusion.
These can include:
The average—and safe—room temperature for an elderly person is around 78 degrees, according to research published in Age and Aging. To prevent an elderly person from becoming too cold, it’s recommended the room temperature never drops below 65 degrees.
A normal adult body temperature, when taken orally, can range from 97.6–99.6°F, though different sources may give slightly different figures. In adults, the following temperatures suggest that someone has a fever: at least 100.4 °F (38°C) is a fever. above 103.1°F (39.5°C) is a high fever.
Everyone’s body runs at a slightly different normal temperature, but the average is 98.6 degrees Fahrenheit, and anything above 100.9 F (or 100.4 F for children) constitutes a fever. While a fever might be uncomfortable (and even slightly worrisome), it’s not inherently bad.
What are some causes of falls? The normal changes of aging, like poor eyesight or poor hearing, can make you more likely to fall. Illnesses and physical conditions can affect your strength and balance. Poor lighting or throw rugs in your home can make you more likely to trip or slip.
Diagnosis of Sepsis and Septic Shock Doctors usually suspect sepsis when a person who has an infection suddenly develops a very high or low temperature, a rapid heart rate or breathing rate, or low blood pressure.
How to Keep Seniors Warm