Exposure to extreme heat can cause illness and even death for some people. But there are several small steps you can take to protect yourself and your loved ones.
We need to keep our body temperature in the range of 35.5 to 37.5°C as this protects our vital organs and allows the body to function normally. Bodies gain heat from both the metabolic processes within and the environment, and heat is lost through the skin by radiation and by sweating.
How you experience heat can be improved by adaptive behaviour, such as staying in the shade, indoors in air-conditioned places and using fans to circulate the air.
Heat-related illnesses occur when heat gain is greater than heat loss; when heat gain from the environment or metabolic processes cannot be effectively dissipated through physiological or behavioural thermo-regulatory processes. These illness range in impact from mild, such as heat cramps to severe or life-threatening, such as heat stroke.
Heat stroke is a medical emergency, leading to rapid death in 10% to 50% of cases and poor outcomes in a high proportion of survivors, according to the World Health Organisation.
Those at greatest risk of heat-related illnesses are people aged 65 years and older, babies and young children, pregnant women and breastfeeding mothers. People who have difficulty communicating, moving around or are bedridden are also at high risk (because they rely on others for drinks and showers), as are older people living alone.
Exposure to extreme heat has particularly adverse effects on people with chronic illnesses such as cardiovascular, respiratory or renal diseases, along with diabetes and obesity, and those with mental illness. These people account for a high proportion of the deaths caused by extreme heat.
People working outdoors also face high risk, especially if they’re working in direct sunlight. Excessive drug or alcohol use increases the risk of heat-related illness the drugs affect thermoregulation and alcohol acts as a diuretic (causes increased urination).
Medications including blood pressure and heart medicine (beta-blockers), water pills (diuretics), antidepressants, antipsychotics and anti-convulsants (seizure medication) and antihistamines (allergy medications) may also affect how the body reacts to heat. And where you live could pay a role in the degree of risk heat poses for you. People living in multistorey buildings, and houses without external shading either from blinds, awnings or vegetation are most likely to be affected.
Access to air-conditioning is clearly protective during extreme heat. This can either be at home or by going to an air-conditioned place such as cinema, shopping centre, community centre, or library.
You should be prepared for extremely hot weather over summer, and ensure that your heatwave plan includes:
1. Setting up fans in living areas and bedrooms. Some people may need assistance from family or carers to do this;