Documents: Special Interest: Garden Musings:

10 Neat Things About Heatwaves
by Dorothy Dobbie
by Dorothy Dobbie

The Local Gardener magazines, Ontario Gardener, Manitoba Gardener and Alberta Gardener, are published by Pegasus Publications Inc.

Drawing on her 30 years' experience as a senior executive in the magazine publishing industry, Dorothy launched Manitoba Gardener in 1998, initially running the business out of her home. Two years later, Dorothy's daughter Shauna, living in Ontario, jumped into the fray with Ontario Gardener. And two years after that, they started Alberta Gardener. Visit us at and register for our "Ten Neat things" newsletter. Watch Shaw TV for garden tips and Listen to CJOB for the Gardener Sundays at 9:08

July 24, 2016

1. The adiabatic effect.

High pressure in the upper atmosphere forces air to sink toward the earth where it hovers like a giant bubble, holding in heat that rises as the pressure is exerted downward. In compressed air forces temperatures to rise even though there is no gain or loss of heat. The adiabatic effect, which occurs when gas is compressed.

2. How's the weather up there?

Tall people over six feet may actually find the weather more clement at their head level than those who are shorter. This is because the temperature is measured in the shade at two metres (five feet) off the ground. However, the closer to the earth, the hotter it is. This ground level temperature can be exacerbated in the sun by as much as 15 degrees F. And stay off surfaces such as dark, dry pavement which absorbs and radiates heat.

3. It's not the heat, it's the humidity.

Relative humidity can make a body so much hotter. Human bodies regulate heat by varying the rate and depth of blood circulation. When it's hot, blood vessels dilate and send blood nearer the surface of the skin through tiny capillaries. Sweat glands open up and water is diffused through the skin as perspiration. We rely on the cooling effect of this evaporating perspiration to reduce skin and hence, blood pressure. When the humidity is high, evaporation cannot take place.

4. Don't eat meat.

High protein foods such as meat cause the body temperature to rise. In the heat, don't eat meat.

5. Murder and mayhem.

Heat waves cause psychological stress that manifests in a rise in violent crime. Heat waves trigger murders, rapes and even civil wars.

6. Wild fires.

Heat waves can cause spontaneous combustion, starting forest fires and other conflagrations, including fires in dried-out potted plants filled with peat moss, fertilizer and Styrofoam. Fertilizer is an oxidizer, adding fuel to spontaneous combustion. Water your potted plants in hot weather and don't use them as ashtrays.

7. Oh, Baby, you're so hot!

Heat waves seem to encourage sexual activity and the result of this action appears to produce more boys than girls. This is odd because heat waves can result in male fertility dropping, lowering sperm counts. One postulation is that the hot spells damage sperm carrying the female X chromosome.

8. How sweet it is.

Sweet things taste sweeter in hot weather, perhaps because heat affects glucose-regulating hormones that increase blood sugar levels.

9. Heat stroke and other heat ailments.

Hyperthermia - heat stroke - is the result of severe body temperature increases and dehydration. It is evidenced by dizziness and fainting, rapid heartbeat, diarrhea, headache, nausea, and vomiting, even death. In heat, hands, ankles and feet may swell. Heat rash can occur (be careful not to get a secondary infection); and heat cramps can seize up the large muscles after heavy exercise and not enough replacement of electrolyte-containing fluids.

10. Dying of the heat.

This is not just a saying. Each year there are 120 heat-related deaths in Toronto alone. Between 1992 and 2001, heat waves in the United States killed 2,190, compared to 880 dead in floods and 150 in hurricanes. Men are more susceptible than women because they sweat more and become dehydrated more quickly. Heat stroke and death can occur quickly. Drink water. Get cool.

Dorothy Dobbie Copyright© Pegasus Publications Inc.

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