It is only the beginning of June, but we have already experienced some very hot temperatures and high humidity. This combination of weather conditions might be considered ideal for some folks, but research suggests it appears to increase the incidence of acute myocardial infarction (AMI) or heart attack leading to death among the elderly – particularly when experienced in conjunction with chronic health conditions.
The Heart Association warns people about the effects of hot weather on their health. Extreme heat can cause dehydration, heat exhaustion and stroke. Factor in high humidity and you can find yourself in a very dangerous situation.
When blood is heated above 37 degrees C, the human body attempts to lose the extra heat by losing water through the skin and sweat glands, altering the rate and depth of blood circulation and, as a last resort, by panting. About 90 percent of the body’s heat is lost through the skin, and most of that is lost through perspiration. Sweating by itself does nothing to cool the body unless the water is removed by evaporation. In order to evaporate the sweat from the body, heat energy is required to change liquid water into the vapour state.
When the humidity is high, much of the heat lost is countered by an almost equal heat gain, and thus the cooling of the body is minimal, leading to overheating. Overheating can cause discomfort at the very least and death at the very worst. Continued loss of water and a variety of dissolved chemicals such as sodium chloride — salt — from the body, if not replenished, can cause dehydration and chemical imbalances. Dehydration depletes the body of water needed for sweating and thickens the blood, requiring more pressure to pump it through the body, thus straining the heart and blood vessels.
Research on the effects of heat and humidity on humans has shown the severity of heat disorders increases with age. Conditions which cause heat cramps in a 16 year old may cause heat exhaustion in a 40 year old and heat stroke in someone over 60.
Seniors are cautioned to limit outside activity when the temperature is above 21 degrees with humidity above 70 percent. With these conditions, the body’s natural cooling mechanisms are affected. During hot summer months, outdoor activity such as exercise, walking, lawn mowing, and gardening should be limited to cooler times of day, such as the early morning or in the evening.
Seniors are also encouraged to increase their water intake to compensate for fluid lost in hot weather. The Heart Association suggests monitoring your fluid intake by weighing yourself in the morning after using the restroom. If your weight is down by two pounds or more you should increase the amount of fluids you consume.
Remember, dehydration can lead to heat exhaustion which can lead to heat stroke. Heat stroke can kill, especially if you are an older adult with a health condition.
On a lighter note – How hot is it? The cows are giving evaporated milk. The chickens are laying hard-boiled eggs. I saw a dog chasing a cat and they were both walking. Hot water now comes out of both taps. You realize that asphalt has a liquid state. You start putting ice cubes in your water bed. Until next week … keep your cool.