Humidex Advisory for Nova Scotia

The Department of Health is advising all Nova Scotians to take proper precautions during the sustained high heat and humidity during the next couple of days.

The humidex is expected to be high today, Aug. 14, and Thursday, Aug. 15, increasing the risk of heat stress and other heat- related illness.

In some inland regions, especially in the Annapolis Valley region, the humidex may reach 40. The conditions in the valley will also be affected by higher-than-normal smog levels resulting in poor air quality.

People who suffer from allergies, asthma, heart disease, emphysema or chronic bronchitis are advised that their symptoms could worsen by exposure to smog.

Those at the greatest risk of heat-related illness include infants and children up to four years of age, those aged 65 or older, people who are overweight, those who overexert themselves during work or exercise and people who are ill or on certain medications.

Heat-related illness occurs when the body's temperature control system is overloaded. The body normally cools itself by sweating, but under some conditions sweating isn't enough. Signs of heat illness include rapid breathing, headache, weakness or fainting, confusion and more tiredness than usual.

The most severe health effect is heat stroke. A person suffering from heat stroke experiences a high body temperature -- greater than 40 degrees Celsius -- hot, dry skin and dizziness or confusion.

"We encourage all people to stay out of the sun and heat as much as possible during this time," said Dr. Jeff Scott, Nova Scotia's chief medical officer of health. "If you must be outside, plan your activities either before noon or in the evening and be sure to drink plenty of fluids."

He offers the following specific advice for when heat and humidity are high:

• Dress in cool, loose clothing and shade heads and faces with a hat or an umbrella.
• Wear sunscreen of SPF 15 or higher to avoid sunburn -- the skin cannot lose heat effectively when burned.
• Never leave infants or young children in a parked car.

People more than 65 years of age are advised to stay in cool areas and use air conditioning or take cool showers or baths. They may not compensate for heat stress efficiently and are less likely to sense and respond to changes in temperature. When the temperature is at or above 32 degrees Celsius, a fan will not prevent heat-related illness.

Overweight people may be prone to heat sickness because of their tendency to retain more body heat. Dr. Scott recommends that they also stay in cool areas and use air conditioning. As well, anyone with a health condition that causes dehydration is more susceptible to heat sickness and should consult their doctor.

Similar in concept to winter's wind-chill factor, the humidex is a measure devised by meteorologists to describe how heat and relative humidity combine to create a more intense perceived temperature. The humidex takes into account the two most important factors that affect summer comfort -- temperature and humidity -- and is therefore a better measure of how stifling the air feels.