Health Matters by Dr.Paul: Heat and Humidex

Given the experts are predicting a hot summers ahead due to climate chaneg, I want time to review the effects of high heat and humidity and list a few prevention tips. We know that the humidity level plays the most important role in heat induced stress and illness. During heat waves, the temperature is measured but the humidity is also recorded and tends to bring up the temperature. This measurement is referred to as the Humidex. Generally, humans can control their internal temperature by sweating. However, under extreme heat and humidity conditions, the body cannot keep up and will suffer from heat stress. The elderly, young children and those with chronic medical, respiratory and heart conditions are more susceptible to heat. 

Humidex combines temperature and humidity into one number. With a Humidex of 20 to 29, there is usually no discomfort. Between 30 and 39, there is some discomfort. A Humidex of between 40 and 45 is associated with great discomfort and over 45 it is considered dangerous.

Heat exhaustion usually occurs after prolonged exposure to heat and/or heavy exercise in the heat resulting in increased loss of body fluids through heavy sweating. The signs of heat exhaustion include:

  • Clammy, pale skin
  • Sweating
  • Dry mouth
  • Tiredness(fatigue)
  • Headache and/or dizziness

Persons suffering from heat exhaustion need to be removed from the heat immediately and given water to drink and cool compresses on their skin. Fortunately, heat exhaustion is not life threatening, and will resolve with rest, fluids and cooling down.        

Heat stroke is dangerous and potentially deadly. The body is so overwhelmed by the it loses the ability to sweat. This results in very high body temperature which in severe cases, can cause brain damage and tragically, even lead to death. The signs of heat stroke include:

  • Very high body temperature  
  • Hot, red and dry skin
  • Absence of sweating
  • Deep or shallow breathing
  • A weak pulse rate
  • Confusion or hallucinations
  • Seizures
  • Loss of consciousness

Heat stroke can occur suddenly and is an emergency requiring immediate medical attention.

Heat Precautions

During Humidex readings between 35 and 39, certain types of outdoor exercise should be toned down or modified, depending on the age and health of the individual, physical shape, the type of clothes worn, and other weather conditions. During a Humidex of 40 and over, all unnecessary activity should be limited.

Here are some other things to help you keep cool and safe

  • Dress young children and babies very lightly
  • Stay indoors during the hottest time of the day (usually mid-morning to mid-afternoon).
  • Air conditioners if available help, even for young babies.
  • If there is no air conditioner, try to stay at the lowest level of the house as it tends to be cooler and keep your home as shaded as possible by closing window blinds and curtains. A fan will help as well.
  • Go to a local mall, store or public library that has air conditioning to cool off if you do not have an air conditioner at home.
  • Drink plenty of fluids. Water is good. It is important to know that children may not feel thirsty but will still need to drink regularly. Avoid caffeine-containing beverages.

On a final note, never leave children or pets inside of a car, as the heat can rise extremely quickly to dangerous, and even deadly levels.

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