University of Vermont Extension 
Department of Plant and Soil Science

Summer News Article


Dr. Leonard Perry, Extension Professor
University of Vermont

Heat may be good for some of your garden plants, but extreme heat may not be good for you.  If you like to garden, keep in mind several sensible tips during hot, muggy weather.

I was surprised to learn from the Centers for Disease Control and Prevention (CDC) website that between 1979 and 1999 there were over 8,000 deaths in the United States from extreme heat.  This is more than from hurricanes, lighting, tornadoes, floods, and earthquakes combined.  Such deaths, or even heat illness can be prevented, especially when gardening.

A body normally cools itself through sweating, sometimes known as ďevaporative cooling.Ē  If the temperature is too high, this may not be enough.  If the air is humid, sweat wont evaporate as quickly, so the body wont cool itself properly or quick enough.  This makes the body feel like the air temperature is even warmer than it is, something often called the ďheat index.Ē  For instance, if the air temperature is 90 degrees F, and the relative humidity is 80 percent, the your body feels like it is 112 degrees F.

Although any individual can experience heat stress, the old (often over 65 years old) and very young are most susceptible as their bodies donít adjust to heat as easily.  Also quite susceptible are individuals overweight, or with heart disease, poor circulation, fever, mental illness, sunburn, and prescription drug use, as these all impair the bodyís ability to cool itself.  Drinks with alcohol, as well as those with caffeine or large amounts of sugar can actually cause the body to lose fluid.  Very cold drinks, while seeming to be appropriate to cool down, can actually cause stomach cramps.

If you are at higher risk, use a buddy system.  Have someone check on you periodically, if not work with you.  Or if you know someone that may be at risk, check on them.

To avoid heat stress while outdoors or gardening, the CDC provides other applicable tips.
*Drink plenty of fluids, keeping in mind the above cautions.  Donít wait until you are thirsty to drink.  If you are doing heavy exertion during the heat, you may need two to four glass of cool (not very cold) fluids per hour.  If your doctor has regulated your fluid intake, this may vary.  I usually keep a quart bottle or water with me in the garden during summer for frequent breaks.
* Replace salts and minerals, which are removed by sweating.  There are many sports beverages on the market which accomplish this.  If on a salt or other mineral diet from your doctor, check first before consuming these or salt tablets.
*Avoid hot foods and heavy meals, which only makes sense and you probably donít want anyway during hot spells.
* Wear appropriate clothing and sunscreen.  Lightweight, light-colored, loose-fitting clothing is best.  Wear a wide-brimmed hat.  Wear sunscreen of SPF 15 or higher to prevent UV damage to skin, applied 30 minutes before going outdoors if possible.
*Schedule your activities for cooler times of the day.  This is usually in the morning or late afternoon.
*Pace yourself. If you are not used to the heat, start slowly.  Accept that you probably wont work as fast, or get as much done, as you would in cooler weather.
*Seek a cooler location if you find yourself getting too hot, or breathing heavily.  Best is indoors in air conditioning, or with a cool shower, or even outdoors with a garden hose or sprinkler.  In very hot or muggy weather, window fans may not cool you sufficiently.  Often a shady area of landscapes can be ten degrees or more cooler on hot days than paved areas such as drives, patios, or urban settings.

If you do get hot, and experience any of a rapid, strong pulse, dizziness, confusion, nausea, or a throbbing headache, you might be experiencing heat stroke.  This is when your body fails to cool itself, and your body temperature rises within minutes by several degrees.  If this occurs, seek cool areas or solutions as above immediately, but do not drink liquids.  Seek immediate medical assistance as well.

Heat exhaustion is a milder form of heat stroke, which often comes on after several days of exertion in the heat, and from improper amount and balance of fluids in the body.  To overcome this, follow the above tips and stop gardening until you feel better.  If you donít get better soon, seek medical help.  Especially prone are the elderly and those with high blood pressure.

A symptom of heat exhaustion, which may occur by itself, is heat cramps.  These are muscle pains or spasms, usually in the abdomen, arms, or legs.  They occur from a depletion of salts in the muscles from heavy exertion.  If you experience these, stop and cool down.  Drink a clear juice or sports beverage.  Donít return to gardening for a few hours after the cramps subside.  If they donít go away in an hour or so, seek medical attention.

Garden smart and safely during hot weather, and you still can get in some quality time outdoors.  The keys are working slower and at cooler times of the day, drinking more appropriate fluids, and taking more breaks in the shade or cool.

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