If you are driving a car and the temperature light comes on, it means that the cooling system of the car is becoming overwhelmed. If you continue to drive the car, the problem will go beyond the cooling system to affect the engine, and eventually the car will stop.
Likewise, in order for the body to function properly, it must maintain a core temperature of 36.7°C–37°C. When it is very hot and humid, the body's natural defense is to sweat profusely; when this happens, the body loses not only water, but also sodium. If this goes on for long enough without replenishing the fluids and electrolytes lost during perspiration*, the body will become dehydrated, and the individual may start having symptoms of heat cramps, heat exhaustion, or heat stroke.
Humidity is a huge factor; in tremendously high temperatures and high humidity, a person will sweat but the sweat will not dry on the skin. The problem with high humidity making us feel hotter is not just that it makes us more uncomfortable, but that we are actually hotter. Our bodies compensate by working harder and harder to cool us down; when sweating does not work to cool us down and we continue to heat up, it leads to overheating and loss of water and chemicals the body needs, leading to heat exhaustion, dehydration and chemical imbalances within the body.
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. As blood goes to the external surface of the body, less goes to the muscles, the brain, and other organs. Physical strength declines, and fatigue occurs more quickly than under normal conditions; mental faculties, such as alertness, may also be adversely affected.
Such effects are more pronounced, and more dangerous, depending on age and overall physical condition; however, young people who are not aware that their physical activity or exercise could be dangerous in humid conditions, are also at risk. Overheating is a serious condition, and can result in the following:
- Heat cramps: Exercising in hot weather can lead to muscle cramps, especially in the legs, because of brief imbalances in body salts. Cramps become less frequent as a person becomes used to the heat.
- Heat syncope or fainting: Anyone not used to exercising in the heat can experience a quick drop in blood pressure that can lead to fainting. As with heat cramps, the cure is to take it easy.
- Heat exhaustion: Losing fluid and salt through perspiration or replacing them in an imbalanced way can lead to dizziness and weakness. Body temperature might rise, but not above 38.8°C; in some cases, victims, especially the elderly, should be hospitalized. Heat exhaustion is more likely to occur after a few days of a heat wave than when one is just beginning. The best defense is to take it easy and drink plenty of water.
- Heatstroke: In some cases, extreme heat can upset the body's thermostat, causing body temperature to rise to 40.5°C or higher. Symptoms are lethargy, confusion and unconsciousness; even a suspicion that someone might be suffering from heatstroke requires immediate medical aid because heatstroke can kill.
In order to avoid the previous mentioned problems, here are some tips to keep you cool in the summer:
- Alter your pattern of outdoor exercise to take advantage of cooler times; early morning or late evening. If you cannot change the time of your workout, scale it down by doing fewer minutes, walking instead of running, or decreasing your level of exertion.
- Wear loose-fitting clothing, preferably of a light color; cotton clothing will keep you cooler than many synthetics.
- Fill a spray bottle with water and keep it in the refrigerator for a quick refreshing spray to your face after being outdoors.
- Try storing lotions or cosmetic toners in the refrigerator to use on hot, overtired feet.
- Keep plastic bottles of water in the freezer; grab one when you are ready to go outside. As the ice melts, you will have a supply of cold water with you.
- Take frequent baths or showers with cool or tepid water.
- Combat dehydration by drinking plenty of water along with sports drinks or other sources of electrolytes.
- If you are wearing a cap or hat, remove it and pour a bit of ice cold water into the hat, then quickly invert it and place it back on your head.
- Avoid caffeine as it promotes dehydration.
- Instead of hot foods, try frequent small meals or snacks containing cold fruit or low fat dairy products. As an added benefit, you will not have to cook next to a hot stove.
- If you do not have air-conditioning, arrange to spend at least parts of the day in a shopping mall, public library, movie theater, or other public areas that are cool.
- Finally, use common sense; if the heat is intolerable, stay indoors when you can and avoid activities in direct sunlight or on hot asphalt surfaces. Pay special attention to the elderly, infants, and anyone with a chronic illness, as they may dehydrate easily and be more susceptible to heat-related illnesses. Do not forget that pets also need protection from dehydration and heat-related illnesses too.
*The article was published in the PSC Newslertter, Summer 2012 issue.