Dehydration, Hyperthermia and Heatstroke: Caring for Older Adults in Summer
Published: 18 July 2021
In Australia, heatwaves have caused more deaths than any other natural disaster over the past 100 years (DEA 2016).
With older adults over 65 being one of the high-risk groups for hyperthermia (along with babies and young children, pregnant women and those with certain conditions) (Better Health Channel 2015a), knowing how to appropriately care for your older clients during the warmer months is crucial.
What is Hyperthermia?
Hyperthermia is an umbrella term comprising several heat-related illnesses that are caused by disruption to homeostasis. Hyperthermia occurs when the body is unable to dissipate as much heat as it is absorbing or producing, leading to a thermoregulation failure (NIA 2016; QAS 2017).
Heat-related illnesses include heat syncope, heat cramps, heat oedema, heat exhaustion, dehydration, heat rash, worsening of existing medical conditions and heatstroke (NIA 2016; Better Health Channel 2015a).
Heatstroke is defined by a body temperature of over 40°C. It is the most serious form of hyperthermia and is a life-threatening medical emergency that may lead to multi-organ failure, disability or death. In order to prevent heat exhaustion from progressing to heatstroke, prompt treatment is essential (QAS 2017).
Up to 80% of heatstroke cases result in fatalities (Better Health Channel 2015a).
Why are Older Adults at Increased Risk of Hyperthermia and Heat-Related Illnesses?
Older adults are more susceptible to dehydration due to changes in the body that occur with ageing, including decreased thirst sensation and decreased renal perfusion (Picetti et al. 2017).
Poor blood circulation, less efficient sweat glands and overall reduced tolerance to sudden or prolonged temperature changes are also age-related risk factors (NIH 2018; Better Health Channel 2015a).
Other reasons why older adults are more likely to experience hyperthermia include:
Being more likely to take medicines that cause fluid loss or altered thermoregulation (e.g. diuretics, some heart and blood pressure drugs);
Having certain chronic conditions including heart, lung or kidney disease, diabetes and mental illness
Living alone or being socially isolated (meaning they have reduced access to heat-health messages and may have nobody around to help if symptoms occur)
Poor hydration literacy
Difficulty recognising dehydration symptoms
Cognitive impairment causing forgetfulness, physical difficulty with drinking, dysphagia or communication issues (meaning the older adult is unable to express their need for water)
(DEA 2016; Aged Care Guide 2020; SA DoH 2013)
Despite this, a 2017 study alarmingly found that dehydration was ‘frequently dismissed’ among aged care residents (Miller 2017).
Furthermore, a 2013 study found that while 38% of surveyed older adults had experienced hyperthermia symptoms during recent heatwaves, only 3% were concerned about their health (SA DoH 2013).
Causes of Hyperthermia
Causes of hyperthermia include:
Being in environments with reduced airflow (e.g. poorly ventilated or confined areas)
Sun exposure, particularly on hot days
Being in hot and crowded environments
(Better Health Channel 2015a)
Factors that may contribute to hyperthermia include:
Clients may also experience an exacerbation of other existing conditions. This is the most common effect of hyperthermia (Better Health Channel 2015a).
First Aid for Severe Hyperthermia (Heat Exhaustion or Heat Stroke)
In the case of an emergency, the priority is to cool the client down (QLD DoH 2017).
Call for medical help immediately.
Move the client from the heat source to a cool, shaded area, lay them down and keep them as still as possible.
Remove the client’s excess clothing.
Place the client in a cool shower
Spray the client with cool water from a hose, or
Wrap the client in a cool, wet sheet and vigorously fan them
Use cool packs under the client’s armpits, on their groin or on the back of their neck.
Monitor the client’s body temperature, continuing to cool them until they reach below 38°C.
If the client is cooled too quickly, they may become hypothermic. Stop cooling the client if they shiver, feel cool to the touch or peripherally shut down.
Give the client small sips of fluid, only if they are conscious and you are confident they can swallow properly.
If the client is unconscious, place them on their side and clear their airway. Perform CPR if the client is unresponsive.
Do not administer paracetamol or aspirin.
(QLD DoH 2017; QAS 2017; NSW DoH 2013)
It is important to note that the symptoms of heat exhaustion and heatstroke may be similar. However, one significant difference is that a client with heatstroke may have dry skin and not be sweating (Better Health Channel 2015).
Practical Tips for Caring for Older Adults in Summer
The following tips will help prevent clients from experiencing hyperthermia on hot days:
Take note of the weather and take appropriate precautions if the temperature is over 30°C. Temperatures of over 37°C are particularly dangerous
Make sure the cooling systems in the home or facility are operating correctly
In addition to water, ensure other fluid options such as jelly, ice-cream or fruit juice blocks are available for clients
Keep curtains and blinds closed in hot weather
Ensure clients’ rooms are at a comfortable temperature and have adequate ventilation
Small amounts of fluid should be given regularly, rather than large amounts given less frequently
Avoid giving clients caffeinated or alcoholic beverages on hot days
Provide frequent, small meals. Consider cold options such as salad and fruit
Encourage clients to wear lightweight, loose, clothing (preferably made from natural fibres) and help them keep their skin covered if they go outside. Ensure wide-brimmed hats and sunglasses are worn
Discourage clients from going outside between 11am and 3pm and limit outdoor activity
Offer clients sponging or tepid showers
Review clients’ medicines during summer months to determine whether there is any increased risk of hyperthermia
Ensure you have access to a working phone in the case of a power failure. Ensure clients’ safety alarm pendants will also work if a power failure occurs
Ensure metal mobility aids or equipment are kept in the shade so that clients do not get burnt
Check for symptoms of hyperthermia
Seek immediate medical help if a client deteriorates.
(DoH 2020; Better Health Channel 2015b; Baptcare 2017)
Managing and Preventing Dehydration
It is crucial to identify and treat dehydration early in order to prevent serious complications and severe hyperthermia (Chan et al. 2018; Mayo Clinic 2019).
In fact, even dehydration equal to a loss of 2% of body weight may adversely affect physiological responses and performance (NRV 2014).
Hydration is influenced by physical, mental and behavioural factors that affect the willingness and ability for people to remain hydrated (Miller 2017). A non-modifiable risk factor for dehydration is older age (Burns 2016). However, while it may not be possible to turn back time, nurses can use this information to modify their practice.
In residential aged care, it is recommended that staff perform hourly checks on clients to ensure that they have access to and are assisted with hydration (Burns 2016).
The Nutrient Reference Values for Australia and New Zealand (2014) recommends that:
Men aged over 70 years consume 10 cups (or 2.6L litres) of water per day
Women aged over 70 years consume 8 cups (or 2.1L litres) of water per day.
Note that this recommendation is an average, and evidently, factors such as very hot climates must be taken into account for the individual’s hydration needs (NRV 2014).
Other factors that may cause a client to require additional fluids include:
Vomiting or diarrhoea
(Better Health Channel 2019)
Healthcare professionals must be careful to follow any additional hydration needs of the individual, for example, fluid restrictions set by specialists. It is thereby also essential to document fluid balance accurately.
Older adults are at increased risk of hyperthermia. Keeping your clients safe during summer is essential, as heatstroke is a life-threatening emergency.
Chan, H Y L, Cheng, A, Cheung, S S S, Pang, WW, Ma, WY, Mok, L C, Wong, W K & Lee, D T F 2018, ‘Association Between Dehydration on Admission and Postoperative Complications in Older Persons Undergoing Orthopaedic Surgery’, Journal of Clinical Nursing, viewed 23 April 2018, https://www.ncbi.nlm.nih.gov/pubmed/29493857