Writing this article on heat and its effects on our bodies was difficult to do on a cold winter morning. However, by the time you read this spring issue, the days will be much warmer with the hot, humid days of summer soon to follow. In fact, average temperatures, especially in the summer, have been getting warmer. This makes the risk of heat-related illness increasingly high.
Recent prodigious snowfalls raise questions about the existence of global warming. However, insight into some of the generators of huge snowfalls can explain the seeming paradox of increasing temperatures and bigger snowstorms.
In winter, higher global temperatures increase the flow of moisture-laden tropical air northward where it collides with frigid arctic air masses that often overlie our region. This collision can spawn massive snowstorms that have been in weather news so much recently.
While no single weather event can indicate climate change (climate is the long-term composite of daily weather), there are some data that help show overall trends. At the Burlington weather service, where climate data has been recorded since the 1800’s, eight of the top 20 snowstorms have occurred since 2000. Of the top ten warmest years, half have occurred since 2000. Of the top ten coldest years, none have occurred since 1969. So clearly, Vermont’s climate has become snowier and warmer since the 1800’s.
So how do we cope with climate change? Surely, the readers of this column will not sweat the consequences of bigger snowstorms. Cross-country skiers tend to have good coping skills when it comes to big snowfalls. What we may not be so good at is dealing with increasing heat.
There are several ways in which heat can make you sick, ranging from minor muscle cramps to deadly heat stroke:
- Heat Cramps seem to be brought on by dehydration, electrolyte loss, fatigue, and strenuous activities to which an athlete is unaccustomed. The cramps are intense muscle spasms not associated with strain or injury. No signs of more severe illness such as heat exhaustion or heat stroke are present.
- Heat Syncope (passing out or fainting) Usually occurs immediately after completing a workout or during a break, such as when reaching a summit. The cause of collapse is low blood pressure resulting from blood pooling in dilated skin circulation where it has been shunted to cool the body. There is also blood pooling in veins that suddenly dilate when muscles are relaxed. The blood flowing to the pumping heart is suddenly insufficient and blood pressure drops precipitously. Lying down will relieve symptoms immediately. If not then more severe heat illness is likely occurring.
- Heat Exhaustion: Flu-like symptoms with nausea, vomiting, headache, weakness and malaise. Body temperature usually 101 to 104ºF. No confusion as is seen in heat stroke. Still sweating. Rapid heart rate. Dizziness with standing.
- Heat Stroke is a multi-system illness characterized by brain malfunction (encephalopathy) and additional organ damage (e.g. kidney, liver, muscle) in association with high body temperatures above 104ºF. Brain effects may be disorientation, headache, confusion, odd behaviour, irritability, coma, and seizure. Without immediate, aggressive medical treatment, death is common.
Treatment of mild illness:
- Stop exercise immediately.
- Get out of the sun.
- Drink cool non-alcoholic, caffeine-free fluids.
- If available, get into air-conditioning.
- Remove as much clothing as is socially acceptable.
- Put cold packs on neck, armpits, and groin.
- Spray yourself with water and sit in front of a fan.
Treatment of more severe illness with confusion or coma indicates heat stroke and requires immediate medical care. The above measures, with the exception of giving oral fluids, should be started immediately while awaiting medical care. The death rate from heat stroke is high, especially if care is delayed.
Risk factors for heat illness:
- Drugs, especially cold and allergy medications. Some supplements, alcohol, diuretics, diet pills.
- High heat and humidity
- Lack of acclimatization.
- Poor conditioning.
- Female sex.
- Non-Hispanic Caucasian.
- Having been raised in a temperate climate.
Acclimatization requires about 2 weeks of training in the heat. This is lost within about 3 weeks when away from the heat.
Prevention of heat illness in hot, humid weather:
- Take frequent breaks.
- Exercise early in the day.
- Avoid sun by exercising on shaded trails.
- Try to use trails that face the north.
- Shed layers as you warm up.
- Replace fluid losses with water or sports drinks.
- Avoid alcohol or caffeine.
This article provided by Dr. George Terwilliger an ER physician who lives in Brattleboro and is a lifelong Vermont resident. He is an avid backcountry skier and has skied many sections of the Catamount Trail.