April 17, 2010

Heatstroke/Sunstroke - Part 2

Part 2 - Causes

Sunstroke results from a failure in your body's cooling system. When its cooling system fails, your body is overwhelmed by excess heat; this is when sunstroke occurs. Anything that disrupts your body's thermostat can increase the likelihood of sunstroke. These may include such factors as underlying medical conditions, medications, physical characteristics, or age.

Dehydration contributes to sunstroke. Dehydration happens when your body excretes more water than it takes in. For example, increased water loss through excessive urination is a common side effect of caffeine, alcohol, and many prescription and over-the-counter medications. When the water supply in your body is low, cells begin to pull water from the bloodstream, forcing organs to work harder. Dehydration can also affect the skin's ability to cool the body efficiently. The heart must pump an adequate supply of blood to the skin in order for the skin to cool the body. When you are dehydrated, the blood's volume is reduced, so the cooling process becomes less effective. The taxing effect on the body escalates into the symptoms of heat-related illness.

Prolonged exposure to the sun contributes to sunstroke. When body fluids are not adequately replenished, sun exposure can cause rapid dehydration. Even on mild or overcast days, the sun can have dangerous health effects. The heat index is a measure calculated by the National Weather Service. It indicates how hot it "feels" outside in the shade when both the air temperature and the relative humidity are considered. In the direct sun, the heat index rises even higher. The following heat indices are associated with these heat-related conditions:

80°F-90°F: Fatigue possible after prolonged physical activity or sun exposure.

90°F-105°F: Heat exhaustion, heat cramps, and sunstroke possible after prolonged physical activity or sun exposure.

105°F-130°F: Heat exhaustion, heat cramps, and sunstroke likely after prolonged physical activity or sun exposure.

130°F and higher: Sunstroke likely with sustained exposure to the sun.

If heat exhaustion is not promptly taken care of, it can quickly progress to heat stroke. Heat stroke is a more urgent matter and is a medical emergency. Symptoms can include warm, flushed skin, little or no sweating, and an extremely high body temperature. Confusion, loss of consciousness, or seizures may also occur. A call to 911 is the best way to get help fast.

April 15, 2010

Heatstroke/Sunstroke - Part 1

This is a large topic, so for simplicity I am dividing it into 6 parts: Basics, Causes, Symptoms, Diagnosis, Treatment, and Prevention.

Part 1, Basics

I live in the north central part of the US, and generally have about four or five months that I need to be concerned about heatstroke. Others have more or less time to be concerned depending on their location.

I had heatstroke as a teenager, but have been able to adapt and have not had a reoccurrence. Yes, I am probably more conscious of what is happening now with that experience.

Summer is the time of year to enjoy being outdoors. When summer arrives here, so do generally high temperatures and high humidity. People with chronic conditions have to be even more careful in the heat than usual, especially with diabetes.

Hot summer weather can cause dehydration very quickly. It is important for everyone to increase their intake of liquids, not just people with diabetes. However, those of us with diabetes, have to know that dehydration can also occur when blood glucose levels are high, regardless of temperature, so when you are outside, it becomes doubly important to increase your intake of fluids.

1. Drink plenty of fluids throughout the day, especially water and even if you are not thirsty. Do not drink sugar-laden juices and sports drinks though -- they can just compound the problem. Beverages containing caffeine in moderate amounts do not seem to affect blood glucose levels. However, consuming large amounts of caffeine over a shorter amount of time seems to raise blood glucose in some individuals.

NOTE:  If it is important to replace electrolytes, then some sports drinks may be necessary and extra testing may be necessary.

2. Exercise or do activities that are more strenuous in the early morning hours or evening hours of the day when temperatures are cooler and the sun is not at its zenith.

3. It is also recommended to check your blood glucose levels often when it is hot outside. Both hyper and hypoglycemia can be a problem during hot weather.

Heat stroke is a form of hyperthermia. This means that you have an abnormally elevated body temperature with accompanying physical and neurological symptoms. Unlike heat cramps and heat exhaustion, two forms of hyperthermia that are less severe, heat stroke is a true medical emergency that can be fatal if not properly and promptly treated. I would urge everyone to be aware of this fact alone.  A 911 call is important for fast action.

In very dry air, sweat evaporates easily, quickly cooling your body; but in very humid air, sweat does not evaporate. It may collect on the skin or run off your body without affecting your body's climbing temperature.

Extremely warm and humid temperatures can quickly overwhelm your body's cooling system - especially when there is not a breeze. When sweating can no longer keep you cool, body temperature quickly rises, causing the symptoms of heat-related illnesses.

Sunstroke is a type of heatstroke. Heatstroke is a condition that occurs after exposure to excessive heat. In sunstroke, also called heat illness, heat injury, hyperthermia, heat prostration, and heat collapse, the source of heat is the sun. Other types of heatstroke occur after exposure to heat from different sources

Heatstroke, including sunstroke, is considered the most severe of the heat-related illnesses. Heat can have punishing effects on your body. After excessive exercise or physical labor, your body can overheat, and you may suffer heat exhaustion.

Heat cramps occur after excessive loss of water and salt; usually resulting from excessive sweating, or after strenuous exercise or labor. During heat exhaustion and heat cramps, the heat, controlling system is still intact, but can be overwhelmed.

It is necessary to know the signs and symptoms of heat exhaustion, too, since the risk is higher in people with diabetes. If heat exhaustion is not taken care of, it can quickly progress to heat stroke. Heat stroke is a more urgent matter and is a medical emergency.

The body normally generates heat because of metabolism, and is usually able to dissipate the heat by either radiation of heat through the skin or by evaporation of sweat. However, in extreme heat, high humidity, or vigorous exertion under the sun, the body may not be able to dissipate the heat and the body temperature rises, sometimes up to 106°F (41.1°C) or higher.

Again - - A call to 911 is the best way to get help fast.

Resting in an air-conditioned room or another cool place and drinking more water should make you feel better. If you suspect heat exhaustion, call your doctor. He or she may want to follow up with an office visit or other interventions. If the doctor is not available, I suggest a visit to an emergency room.

Those most susceptible to heat/sun strokes include: infants, the elderly (often with associated heart diseases, lung diseases, kidney diseases, or who are taking medications that make them vulnerable to heat strokes), athletes, and outdoor workers physically exerting themselves under the sun.

The summer heat can also be a concern when trying to carry supplies such as insulin, meters and strips with you. Insulated bags with small refreezable gel packs are good for keeping things cool. Keep equipment out of direct sunlight as much as possible.

With some advanced planning and special considerations, summer can still be a safe and enjoyable time of year.