Staying Cool
(Part 1)
Most of us enjoy summer and all that it brings including warm weather, time outdoors and alfresco dining, yet summer can also bring a few unexpected surprises. This is the first of a two-part series looking at common summer problems.
Introduction
Hot weather can take a toll on our wellbeing. High summer temperatures and humidity can stress the body. Some people are particularly at risk of hot weather-related problems. More Australians have died from severe heatwaves than from all other natural disasters combined.
Why is humidity a problem?
High humidity affects the body’s ability to cool itself. In humid conditions perspiration doesn’t evaporate quickly and the body can’t release heat as quickly as it may need to. Factors such as age, obesity, fever, dehydration, heart disease, mental illness, poor circulation, sunburn, prescription drug use and alcohol also affect our ability to cool down.
Who’s at greatest risk of hot weather-related problems?
The elderly (>65 years), young children (<2 years) and people with chronic illnesses (e.g. heart or respiratory disease, diabetes, circulatory diseases, high blood pressure, mental health problems) are at greatest risk of hot weather problems. Young and old folk struggle to remain hydrated in hot weather because their nervous systems aren’t robust enough to manage body temperature effectively. Older people are also at increased risk of heat stress and heat stroke because of frailty, use of certain medications (eg diuretics which dry out the body) and living alone.
What is heat stress and heat stroke?
Heat stress arises when a person is unable to cool themselves to maintain a healthy body temperature. Causes of heat stress include dehydration, lack of air flow (e.g. being in a poorly ventilated space), sun exposure on very hot days, hot/crowded conditions and bushfires. Heat stress can lead to minor problems (e.g. heat rash, cramps) or serious problems like heat stroke (a severe form of heat stress). Heat stroke is the most severe form of heat illness and is a life-threatening emergency.
How can you tell if someone has heat stroke?
Features of heat stroke include:
- a high body temperature (40 Celsius or higher)
- an altered mental state or behavior (e.g. confusion, agitation, slurred speech, irritability, delirium, seizures, coma)
- changes in skin and sweating (e.g. in heat stroke brought on by hot weather the skin feels hot and dry; in heatstroke brought on by strenuous exercise the skin may feel moist)
- nausea and vomiting
- flushed skin (the skin may turn red as body temperature increases)
- rapid and shallow breathing
- increased heart rate (heat stress places a tremendous burden on the heart to help cool the body)
- headache.
How is heat stroke managed?
An ambulance should be called immediately. Delay in managing heatstroke increases the chance of permanent injury or death. While waiting for medical help, get the person to a cool shady area and lay them down. Do not provide drinks. Remove excess clothing and wet the skin with water or wrap the person in wet cloths and fan him or her continuously. If medical attention is delayed, seek further instructions from ambulance or hospital emergency staff.
Are heat stress and heat stroke preventable?
To prevent heat stress/heat stroke, drink plenty of water, stay indoors or in the shade and minimise activity (e.g. exercise, renovating, gardening). Steps should be taken to minimise heat stress when the temperature is forecast to be around 30 degrees Celsius or over.
Can you discuss dehydration?
Dehydration is excessive loss of water from the body. It’s usually caused by excessive sweating (eg due to heat), vomiting or diarrhea. Dehydration can occur anytime but is more common in summer. It arises when fluid intake doesn’t replace fluid output (eg sweating). It’s important to know what the features of dehydration are (see table).
Recognizing Dehydration in Adults
Mild to moderate dehydration
- Dizziness
- Light-headedness
- Dry mouth
- Increased thirst
- Less urine than normal, lower volume & darker colour
- Headache
Severe dehydration
- Very little urine or no urine output; any urine produced is a concentrated deep yellow/amber colour
- Pronounced dizziness or light-headedness (may prevent normal standing/walking)
- Rapid heart rate
- Fever
- Lethargy
- Confusion, Seizure or shock, Coma
How is dehydration treated?
Management of dehydration depends on the severity of symptoms. Severe dehydration is a medical emergency, requiring urgent medical care. Mild dehydration may be managed at home by drinking more fluids (many sports drinks can help restore body fluids, electrolytes, and salt balance). If in doubt about managing dehydration, seek medical advice.
Any final words?
The best way to avoid common hot weather problems like dehydration, heat stress and heat stroke is to drink plenty of water or other non-alcoholic beverages and to carefully plan and time strenuous activities, or reschedule them to cooler times of the day.
Next week we’ll look at other ways to improve your wellbeing in summer.
Further Reading
Contact local councils or state health authorities for information on local environmental issues that may affect health and wellbeing.
Victorian State Government. Better Health Channel. Heat stress and heat-related illness
https://www.betterhealth.vic.gov.au/health/healthyliving/heat-stress-and-heat-related-illness
Victorian State Government. Better Health Channel.. Heat stress – preventing heatstroke
https://www.betterhealth.vic.gov.au/health/healthyliving/heat-stress-preventing-heatstroke
Victorian State Government. Better Health Channel. Heat stress and older people
https://www.betterhealth.vic.gov.au/health/healthyliving/heat-stress-and-older-people