Hot summer weather can pose special health risks to older adults, according to LSU AgCenter nutritionist Beth Reames.

“Older people are at high risk for developing heat-related illness called hyperthermia because the ability to respond to summer heat can become less efficient with advancing years,” Reames said.

Heat fatigue, heat syncope – sudden dizziness after prolonged exposure to the heat – heat cramps, heat exhaustion and heat stroke are commonly known forms of hyperthermia. Symptoms of heat-related illnesses may include headache, nausea, muscle spasms and fatigue after exposure to heat.

“Both an individual's general health and lifestyle may increase the threat of a heat-related illness,” Reames said. “Factors increasing the risk of hyperthermia include age-related changes to the skin, such as poor blood circulation and inefficient sweat glands; heart, lung and kidney diseases, and high blood pressure or other conditions that require changes in diet.”

Lifestyle factors also can increase risk of hyperthermia, including extremely hot living quarters, lack of transportation, overdressing, visiting overcrowded places and not understanding weather conditions.

Reames said hot weather can lead to body water loss, dehydration and heat stroke.

Dehydration is the reduction of total body water and may be due to limited intake of fluids and fluid loss.

“Dehydration may increase the severity of an illness as well as the risk of death,” she said. “Even small losses of body water can impair activity and judgment. Studies show senior citizens may not drink sufficient fluids, and they may also be taking medications, such as diuretics for high blood pressure, which cause fluid loss.”

According to the Institute of Medicine of the National Academies of Science, which sets dietary recommendations for nutrients and water, the recommended daily intake of fluids should be approximately 11 cups of total water from all beverages and food for women and 16 cups for men.

“Although most people can meet fluid needs by drinking when thirsty and regularly consuming beverages at meals, prolonged physical activity and heat exposure will increase water losses and may raise daily fluid needs,” Reames explained. “In very hot weather, very active individuals often have daily total water needs of six quarts or more, according to several studies. It’s also important to remember that water needs vary from day to day.”

Both beverages and food supply water. About 80 percent of people's total water intake comes from drinking water and beverages, and the other 20 percent comes from food.

Solid foods may contribute about four to five cups of water each day. Many fruits and vegetables are 90 percent fluid.

According to the Food and Nutrition Board, drinking caffeinated beverages doesn’t lead to total body water deficits. These beverages can be consumed to help meet hydration needs along with other beverages and food.

Information to help increase fluid intake, especially in hot weather includes:

– Water is a great fluid replacer. Drink cool water because it’s absorbed faster, and you’ll usually drink more of it because it tastes better.

– Water can come from all kinds of beverages and food, including juice, milk, soup, tea, coffee and soft drinks. Plain water is great, too. Remember that juice, milk and soup offer other nutrients as well.

“Try drinking fruit juice diluted with plain water or sparkling water for a refreshing lift,” Reames said. “Some beverages, especially those containing alcohol, may lead to loss of body water.”

The National Institutes of Health recommends that older people, particularly those with chronic medical conditions, stay indoors on hot and humid days, especially when an air pollution alert is in effect.

Reames says people without air conditioners should go to places such as senior centers, shopping malls, movie theaters or libraries.

Cooling centers, which may be set up by local public health agencies, religious groups and social service organizations in many communities, are another option.

For additional information about eating healthfully, contact the LSU AgCenter office in your parish.

Johnny Morgan