Body Temperature in the Elderly: What’s Too High, Low and Just Right

The ideal body temperature for adults is commonly said to be 37° Celsius. But in fact there is a lot of variation in people’s natural body temperatures. Some people really do “run hot,” while others tend to be cold, and body temperature also rises and falls at different times of the day.

Moreover, it’s an observed fact that elderly people tend to have lower body temperatures. This means it’s extra important for older people and their caregivers to monitor body temperature and ensure it’s not too high or too low for safety.

But what is “too low” for an older person, if their body temperature will naturally be lower? For that matter, what temperature is dangerous for elderly people with a fever – is that number the same as for younger people? And why are these temperatures so important?

Read on as we answer these questions and more.

Overly low body temperature

Let’s start by exploring the “too cold” side of the thermometer.

What causes low body temperature in elderly people?

As we’ve said, it’s common for older people be cold when others are comfortable in a room. Why do the elderly feel cold more easily? There are several possible reasons:

• A slower metabolism
• Less fat under the skin, especially in the hands and feet
• Poor circulation
• Dryer skin
• A slower bodily response to cold after drops in temperature.

Additionally, some older people’s medications, such as beta blockers, can also have the side effect of lowering body temperature. Lastly, some medical conditions, such as anaemia, can cause feelings of being cold. If an older person is often uncomfortably cold, it might be worth talking to a GP to ensure there are no underlying problems.

What body temperature is dangerous for elderly people if they’re too cold?

According to the NHS, a person with a body temperature below 35° Celsius has hypothermia, which is a medical emergency. Obviously, you want any older person’s body temperature to be above this point. In fact, older people’s susceptibility to cold – for the reasons we mentioned above – means that they are at greater risk of hypothermia, so it’s important to be extra careful to protect their body temperature from dropping too much. It’s also worth noting that being in rain or cold water can also lower an older person’s body temperature and increase risks of hypothermia.

Since natural body temperature varies during the day and for each individual, there is no hard and fast rule about what the perfect body temperature is. Actually, although 37° Celsius is the figure typically cited as “normal” body temperature, studies have found that body temperature for all adults seems to have been decreasing since the mid-1800s. 37° Celsius may not be the norm after all.

What might we expect an older person’s body temperature to be? One review of studies into human body temperature found that people aged 60 and older had an average temperature by mouth of 36.42° Celsius, although of course there was variation. It may be wise for an older person to track their own body temperature and learn what’s normal for them so that they can be aware when their temperature rises or falls beyond that range.

All this being said, one thing that caregivers of older people can do to protect seniors from cold is to ensure that the room temperature in their living spaces is adequate. As we mentioned in a previous article on the ideal room temperature for older people, experts generally agree that the minimum safe room temperature is 18° Celsius. For some seniors, especially those with long-term health conditions, room temperatures may need to be a little bit higher.

Why is low body temperature dangerous in the elderly?

Why do all of these numbers matter? One reason is that when people are in cold spaces, such as a room colder than 18° Celsius, their blood pressure rises, increasing risks of cardiovascular emergencies like heart attacks and strokes. That’s especially concerning for elderly people who already have high blood pressure or heart conditions.

Cold room temperatures also cause airways to tighten, which is risky for older people with breathing conditions like chronic obstructive pulmonary disease (COPD).

Given these risks, it’s clear why the cost-of-living crisis continues to be a serious concern for the elderly. Older people need to have sufficiently heated living spaces to protect their health.

Overly high body temperature

So, we know that low body temperatures can be risky for the elderly. Unfortunately, that doesn’t mean we don’t have to be concerned about high body temperatures – these can be very risky too.

What causes high body temperature in elderly people?

Some of the reasons why older people are more susceptible to cold also make them more susceptible to heat and heatstroke in hot weather. Elderly people’s bodies just respond more slowly and less effectively to any changes or extremes of temperature. Also, they may not sweat as much, and they may just not be able to feel when they’re being overheated.

Dementia is a particular concern when it comes to overheating in older people for just this reason – a senior with dementia might just not notice that they are too hot.

However, hot weather isn’t the only cause of high body temperature in older people. Fevers due to infections, sepsis and other medical concerns can also cause elevated temperatures.

What temperature is dangerous for elderly people if they’re too hot?

The NHS guidance on fevers gives 38°C as its general benchmark for a fever. However, it also notes that there is individual variation in body temperatures, so that number isn’t the only factor that matters. Shivering, sweating or warm skin can all be signs of a fever too.

As a matter of fact, there are some concerns that fevers are being missed in the elderly because older people’s body temperatures are naturally lower, so their fevers may be lower as well – perhaps not reaching that mark of 38°C. At the height of the Covid pandemic, for example, researchers at King’s College London advised that temperatures of 37.4°C or higher for people over 65 should be considered signs of fever possibly indicating Covid infection.

Why is high body temperature dangerous in the elderly?

High body temperature can strain an older person’s body, which is likely to already be more fragile. In particular, NHS advice for care homes during heatwaves warns of increased breathing problems (perhaps due to pollution) and stress on the heart during hot weather.

How to manage body temperature in the elderly

Clearly, it’s crucial for older people’s body temperatures to stay moderate, neither too high nor too low. It’s also essential for room temperatures to be within a safe range. For both high and low temperatures, an ounce of prevention is worth a pound of cure.

In cold weather, rooms that an older person uses should be heated at least to 18°C. If an older person needs to go outdoors in the cold, they should be bundled up warm and possibly wear a scarf over their mouth to mitigate the harsh effects of cold air.

In hot weather, older people should be very careful to drink enough water, so they don’t become dehydrated. They should be sure to rest and not over-exert themselves.

In both cases, it can be helpful to have a way to call for help if needed. This is especially important since older people may not feel the signs of being overheated or too cold in their body. They may not be aware they’re too hot or cold until they start feeling seriously ill.

A one-touch personal alarm can be a game-changer here. Both high and low body temperature can cause an older person to feel confused and muddled, but a one-touch alarm keeps things simple so that it’s easy to call for help even when an older person is feeling too confused to use a phone.

You can also buy personal alarms that offer temperature alerts, allowing family and friends to keep an eye on an older person’s environment and make sure it’s not too hot or cold. Again, since elderly people may not sense that their living space is too hot or cold, this provides an extra layer of protection to keep them safe.

Lastly, if an older person finds themselves suddenly fainting due to heatstroke when they weren’t aware they were overheated, an automatic fall detection alarm can raise an alert when it senses a fall, without the need for any input from the user at all.

Stay safe in any temperature with SureSafe

A leader in personal alarms for the elderly, SureSafe specialises in high-quality, easy-to-use devices to keep older people secure all the time, even during periods of extreme hot and cold. If you’d like to chat more about how our personal alarms can offer peace of mind for the elderly and their loved ones, why not call us at 0800 112 3201 or reach out via our live chat? Alternatively, you can request a call back, and we’ll ring you back as soon as possible.