Hot, humid weather may increase the risk of hospitalization for people who have lung disease, particularly for those over age 75, a recent study suggests.

Researchers tracked weather data and hospital admissions in 12 European cities for a minimum of three years. They used an indicator called the "maximum apparent temperature," which is an index of thermal discomfort based on air temperature and dew point temperature. It accounts for the combined effect of temperature and humidity, which, especially on hot days, can influence the body's ability to cool itself by evaporation or perspiration.

After also taking air pollution levels into account, the researchers found that in most cities, for each one-degree increase over 90 percent of the maximum apparent temperature, respiratory disease-related hospital admissions increased for all ages, but especially for those over age 75.

To avoid heat-related illness on hot days, try to stay in an air-conditioned location (at least two hours a day during the hottest part of the day, if possible). Also, drink plenty of liquids—water or fruit and vegetable juices are best. Avoid drinks containing caffeine or alcohol, which make you lose more fluids. Dress in light-colored, lightweight clothes made from natural fabrics. And don't overexert yourself.

Source: American Journal of Respiratory and Critical Care Medicine Volume 179, page 383; March 1, 2009

Publication Review By: Peter B. Terry, M.D., M.A.

Published: 12 Aug 2013

Last Modified: 12 Aug 2013