Our body has some in-built mechanisms to help it adapt to changes in the environmental temperature. However when the changes are extreme and last for long durations, the protective mechanisms may fail, and the person may suffer from illness. The following factors increase risk of adverse effects of extremes of temperature change on the human body.
1. Infants and elderly people.
2. People who are exposed to the sun for prolonged periods, e.g. soldiers, farmers.
3. Individuals with medical disorders like diabetes mellitus, cardiovascular disease, and obesity.
4. Poorly insulated and ventilated homes, congested neighborhoods or slums.
5. Sedentary life styles.
6. Low socio-economic class.
□ HEART STROKE (SUNSTROKE)
It occurs when the body can no longer control its temperature by sweating as in the following conditions. It can prove to be dangerous.
1. Very high environmental temperature.
2. Prolonged confinement in hot atmosphere.
3. Consumption of alcohol.
4. Illness like malaria.
The conditions is diagnosed by the following features.
1. There is restlessness, headache, dizziness, and discomfort.
2. The skin is hot, flushed, and dry.
3. The pulse is bounding.
4. The body temperature is 40°C or higher.
5. Breathing is noisy.
6. Muscular cramps may occur.
7. The victim may become unconscious.
First-aid
1. Move the victim to a cool place. Place him in half sitting position with head and shoulders supported if he is conscious, and in recovery position if he is unconscious.
2. Remove his clothing.
3. Sprinkle cold water on his body or wrap him in a thin wet sheet. Start a fan to cool his body.
4. Apply ice cap with ice pieces over the head and neck.
5. A cold water enema can be given.
6. Record his body temperature every 10 minutes. Do not let it fall below 102°F. At that stage wrap him in a dry sheet and keep the fan on so that the temperature does not rise again.
7. Give him cool water to drink. Maintain his hydration.
8. Shift him to a hospital if he does not respond to treatment.
□ HEAT EXHAUSTION
It occurs in hot and humid environment after heavy and prolonged sweating either due to exposure to the sun or working in a close, hot atmosphere like factories, with failure to replace salt and water. The condition is diagnosed by the following features.
1. Restlessness and exhaustion are present. Faintness may be experienced.
2. Headache, dizziness, nausea, vomiting are present.
3. Sometimes there are abdominal cramps, or cramps in the limbs.
4. Temperature may be normal or subnormal.
5. Skin may be cold and clammy.
6. Breathing is fast and shallow.
7. Temperature is normal or slightly elevated.
8. There is pallor.
9. There is loss of appetite.
10. There may be shock.
First-aid
1. Place the victim in supine position in a cooler place with fresh air.
2. Give plenty of cold water (250 ml every half hour) with salt in it (2 teaspoons in 1 liter of water). Fruit juice may be given too.
□ HEAT CRAMPS
They occur when one replaces the fluid lost in sweat by drinking water without salt. The conditions is diagnosed by the following features.
1. There are intermittent painful contractions of skeletal muscles in the body.
2. They occur in those muscles that have been involved in strenuous activity, usually those of the legs.
3. Body temperature is normal or low.
4. The cramps last a few minutes and generally disappear spontaneously.
First-aid
1. Replace body sodium with salt tablets or electrolyte solutions.
2. Shift him to a hospital if his condition is severe or does not respond to treatment.
□ HOW TO PREVENT HEAT INJURIES ?
1. Stay indoors during heat waves. Wear a minimum of clothing that is light in colour, cool and loose fitting.
2. Improve ventilation in the house, use shades and drapes to cut direct sunlight.
3. Limit the strenuous activities to the cooler times of the day.
4. Cook food in the early morning or late evening to avoid heating up the house during the hot part of the day.
5. Use exhaust fans and vents over stoves and ovens to help remove heat from the house.
6. If necessary, expose yourself to hot weather gradually.
7. Use an umbrella or a wide brimmed hat and walk in the shade if you must go out.
8. Take plenty of fluids and salts.
SUNBURN
It occurs after excessive exposure to the blazing sun. It is seen at high altitudes in winter due to exposure to ultraviolet rays. The condition is diagnosed by the following features.
1. There is itching over the burn.
2. The skin is red, swollen and painful.
3. In mild cases there are superficial burns. Severe cases have painful blisters.
First-aid
1. Place the patient in a cool place.
2. Sponge the affected parts with cold water.
3. Apply a soothing cream like a cold cream.
4. Shift a severe case to a hospital.
HYPOTHERMIA
Fall of the body temperature below 35°C is called hypothermia. Mild and moderate cases are reversible, but recovery is unlikely if the body temperature falls below 26-24°C. Hypothermia occurs in the following conditions.
1. Very low environmental temperature without adequate protection in the form of warm clothes, properly heated house etc.
2. Prolonged immersion in cold water.
3. Wearing wet clothes.
4. Exhaustion in cold climate.
Severity varies with age and physical condition of the individual. Consumption of alcohol or drugs and some problems like diabetes mellitus aggravate this condition. It is diagnosed by the following features.
1. The skin is very pale and abnormally cold to touch.
2. There is loss of muscle coordination.
3. Speech is slurred.
4. The victim is irritable, confused, and restless.
5. He may become unconscious.
6. Breathing becomes increasingly difficult.
7. Cardiac activity drops.
First-aid
1. Place the victim in supine position in a warm place. If he is unconscious, place him in recovery position.
2. Cover his body with a woolen blanket.
3. Remove his clothes if wet and replace them with dry, warm clothes.
4. Do not rub or massage the limbs.
5. Do not give him alcohol.
6. Resuscitate if cardiorespiratory arrest develops.
7. Shift him to a hospital immediately.
FROSTBITE
During very cold weather, especially if there is also a strong wind frostbite occurs in the ears, nose, chin, hands and feet. The condition is diagnosed by the following features.
1. Initially there is a white patch on a red face. Then it changes to mottled blue colour.
2. Pickling pain is felt in affected part.
3. The exposed part becomes cold, painful and finally numb.
4. It becomes waxy white in appearance.
5. Prolonged freezing causes irreparable damage.
First-aid
1. Warm the body gradually. Place the injured part in hot water if available. It is better to warm him by dry or radiant heat.
2. Elevate the affected parts to relieve swelling and pan.
3. Take the patient to a closed room.
4. If the frozen part is on the face, cover it with a gloved hand until normal colour and sensation return.
5. Remove his tight gloves, boots, socks, rings etc. in case of frostbite of fingers or toes. The hand may be placed under the clothing in the axilla. Wrap the feet in a warm cloth.
6. Do not rub the frozen part with anything.
7. Give him warm drinks. Do not allow the victim to smoke.
8. Shift him to a doctor or hospital immediately.
□ TRENCH FOOT
It occurs when there is exposure to temperatures above the critical tissue temperature in presence of moisture over prolonged periods. Predisposing conditions are malnutrition, deficiency of proteins and vitamins, and dehydration. The condition is diagnosed by the following features.
1. There is hyperemia of the part.
2. The affected part feels numb.
3. Pain, itching and tingling, and paresthesia develop.
4. Blisters appear later.
5. Infection may develop locally.
First-aid
1. Rewarm the part gradually.
2. Shift him to a doctor’s clinic.
□ CHILBLAIN
It is an allergic reaction to cold and dampness in susceptible individuals. There is patchy constriction of blood vessels of the skin associated with it. It may progress to trench foot if not treated adequately. The condition is diagnosed by the following features.
1. The toes become red. There is intense itching.
2. Severe pain develops.
3. Blisters and ulcers may develop. First-aid
1. Warm the part gradually.
2. Shift him to a doctor’s clinic.
Safety from cold injuries
1. Dress in warm clothes. Wear several layers of loose, warm clothes rather than a singe thick garment.
2. Cover vulnerable parts well.
3. Apply protective cream to the face prior to exposure.
4. Plan activities carefully to minimize exposure.
5. Avoid vigorous washing of the face and shaving until after the day’s work is done rather than early in the morning.
6. Use mittens rather than gloves for hand protection.
7. Do not use excessive heat to thaw frozen tissues.