Posted by & filed under Noah's Notes.

Summer is here and after the winter of 2015 we rightly expect to take advantage of as many opportunities as possible to enjoy the warm weather and the beauty of our lakes, rivers, seashore and woods.  Most of the time in summertime in Maine, we are blessed with comfortably warm days and comfortably cool nights.  But there are days when the heat can become a risk and that risk can be elevated for susceptible people.

Children can get a heat rash (called Miliaria) which can cause itching or a burning sensation.  It usually resolves once the skin is cooled, either by moving to a cooler room or applying cool compresses or taking a cool bath.  Young children are especially susceptible to the very high temperatures that occur very quickly in a car left in the sun.  This is a very unsafe environment for children and they simply should never be left in a car in the heat.

Older people can develop edema, or swelling, in their hands and feet as a result of heat exposure, and exposure to heat can also cause fainting in susceptible people (called heat syncope).  The elderly, those with chronic illness, or people on certain fluid medicines or blood pressure medicines can be more prone to this problem.  This can occur while the body temperature remains normal, and treatment consists of moving to a cooler area, lying down and elevating the legs.

Heat cramps can occur in the legs, arms and abdomen and can be very painful.  Again some people are more susceptible than others, and stretching and moving to a cooler environment can help.  I experienced this phenomenon one time on a long bike rife in high heat and humidity and it is very unpleasant!  Less commonly a syndrome called heat tetany can occur.  It results from hyperventilation due to heat, a change in acid/base balance in the body and resulting symptoms like spasms of the hands and feet and tingling around the mouth.  A quiet, calm and cool environment can help, but the temperature should be checked and if it is elevated medical attention should be sought immediately.

Heat exhaustion occurs in people with heat exposure and an elevated temperature (up to 104 F) and includes symptoms like a rapid heart rate, sweating, nausea, vomiting, headache, weakness, fainting, profound thirst and confusion.  This is a potential emergency and medical evaluation should be an immediate priority.  Often the body’s electrolytes (sodium, potassium, etc.) are normal but they can be abnormally low.  Treatment can consist of cooling and drinking fluids like sports drinks, or IV fluids may be necessary.  Children, the elderly and people with chronic diseases are particularly susceptible.

Heat stroke occurs with heat exposure when the body core temperature exceeds 104 F and there is confusion or altered mental status.  In some instances the person affected by heat stroke will stop sweating  When heat stroke does not involve exertion it is most common in children who are either unable to exit  a very hot environment (for example, the parked car) or who have illnesses or are on medications (some meds for ADHD) which make them susceptible.  When heat stroke is related to exertion it tends to occur in young adults involved in heavy exertion (work or athletic events or military training) in conditions of high heat and humidity.  When relative humidity exceeds 75% our body’s self-regulation fails to adapt fully in most circumstances (because our perspiration won’t evaporate rapidly enough).  Heat stroke is a life threatening medical emergency and aggressive treatment with cooling, fluids, some medications and other interventions require hospitalization.

All of these problems are best approached by a a carefully planned approach to prevent the problems in the first place.

  • If you are not used to hot temperatures allow yourself to gradually adjust to them through limited exposure and exertion at first.
  • Restrict your activity in high heat or in high heat and humidity to that which you can comfortably accomplish.
  • Sporting events should be curtailed in high risk situations.
  • Hydration breaks during active times are important.  Rest and fluids can be very effective.  Interestingly, sport drinks are more likely to lead to adequate hydration than water, simply because people are more likely to drink more of them.
  • Light, loose fitting, lightly colored, absorbent clothing is very helpful.

Here’s wishing you all a safe, enjoyable and comfortably warm summer!



Noah Nesin, MD

Dr. Nesin, Vice President of Medical Affairs for PCHC, is a family doctor with 30 years of experience.

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