PERSONAL COOLING

Your body naturally adjusts to the temperature of your environment. This process is called acclimatisation and plays an important role in how you tolerate heat and cold.

Acclimatisation occurs over a period of about two weeks in healthy people. The process is faster in response to heat, but slower in the cold.

Your physical condition, age, and other factors also affect how your body copes with heat and cold. For example lean people tolerate heat better than obese people.

As a person ages the body’s response to temperature change (i.e. sweating in high temperatures and shivering in low temperatures) is delayed and reduced.

Evaporation of sweat is the most effective bodily cooling process. If you have air circulating next to your skin, it will help to evaporate the perspiration, and this will make you feel cooler. Typically, the air flow created by a fan provides a similar improvement to comfort as reducing the air temperature by around 3°C. Wearing short sleeves maximises this benefit.

Staying hydrated is key. If you don’t drink enough water, you can start to become unwell, with symptoms of headache and tiredness. Remember, beverages with alcohol, caffeine and high sugar content are not as effective at keeping you hydrated.

Heat can cause illness such as cramps, heat exhaustion and heat stoke. More importantly heat can worsen the condition of someone who already has a medical issue such as heart disease or diabetes. For information on staying healthy in the heat visit www.health.vic.gov.au/environment/heatwaves

Try using a spray bottle to spray water on your face. You can also carry around a wet face washer on the back of your neck, or bathe your feet in a basin of water. At night you can try spraying your sheets before going to bed, or have a damp towel handy.

A very cold shower or bath will lower your body temperature so quickly that the body will scramble to raise it again to regain homoeostasis, or balance. As a result it’s better to use lukewarm water (between 20°C and 30°C) rather than very cold water. This should be cool enough to lower the deep body temperature but warm enough not to restrict the blood flow to the surface of the skin.

Natural fabrics like linen and cotton absorb sweat and allow air circulation to your skin. They’re much better than man-made fibres like polyester, which can leave you hot and uncomfortable.

When it comes to the colour of your clothes, white is good if you’re out in direct sunlight a lot – it will reflect the heat better than any other colour. So wear lightweight, lightcoloured, loose clothing that covers as much of your skin as possible when outside in the sun. But if you’re spending time in the shade or indoors, black or dark short sleeved clothing is more effective as it radiates out heat into your environment, cooling you down.

Dampening your clothes can also help. In order for the water to evaporate (changing its state from a liquid to a gas) there needs to be an input of heat energy. This energy will come from the heat of your body, which produces a cooling effect to your skin, lowering your body temperature. If you use a fan as well, the air blowing over your skin speeds up the process of evaporation, helping you to feel even cooler.

Rushing around or exercising vigorously in hot and humid weather can be challenging and even dangerous. Try to schedule outdoor activities such as gardening or trips to outdoor shops and markets, for earlier or later in the day, and avoid physical exertion during the hottest part of the day between 11am – 4pm.

If your accommodation is too hot, consider going to a cool public place such as an air conditioned store, shopping centre, movie theatre, gallery or public pool to keep cool, or visit a friend or family member that has an air conditioned home. The Free Bus in Wollongong also has air conditioning.