Humidex Advisory for Nova Scotia

A humidex advisory has been issued for Nova Scotia by Environment Canada. The sustained high heat and humidity means everyone in the province should take precautions to avoid heat stress and other heat-related illnesses.

Those at greatest risk of heat-related illness include infants and children up to four years of age, people 65 years of age or older, people who are overweight, people 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 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 over 65 years of age are advised to stay in cool areas and use air conditioning or to 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. And when the temperature is in the high 90s or higher, 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.

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. Because it takes into account the two most important factors that affect summer comfort -- temperature and humidity -- the humidex can be a better measure of how stifling the air feels than either one of the factors alone.