Heat and humidity conspire for discomfort, danger

(AP) -- When it comes to the discomfort and health risks of the current heat wave, it's not just the heat or the humidity - it's both.

The temperature conspires with the amount of moisture in the air to make it hard for the human body to cool itself.

When people get hot, the body tries to cool down by moving extra blood to the skin and by sweating.

Blood in the tiny vessels near the skin can dissipate heat into the air, if the air is cooler than the body. But that doesn't work if the air is as hot as the body or hotter.

Sweat helps, because when water evaporates it removes heat. But the more moisture already in the air - the higher the humidity - the less evaporation can occur.

Those two processes account for more than 90 percent of the body's ability to dissipate heat, and when they aren't working, trouble can come from , and even death.

not rated yet
add to favorites email to friend print save as pdf

Related Stories

Weather conditions could results in cattle heat stress

Jul 19, 2011

Cattle producers should be aware that forecasted weather conditions could result in significant heat stress issues in cattle. The US Meat Animal Research Center predicts danger or emergency conditions through most of South ...

Heat stress in older people and people with chronic diseases

Aug 24, 2009

People over the age of 60 are the most vulnerable to heat waves, with 82% to 92% more deaths than average occurring in this age group. Risks for heat-related illness or injury - such as heat stroke, heat exhaustion and heat ...

Hot town, summer in the city

Jul 15, 2010

Heat waves may cause increased mortality but, until now, there has been no single scientific definition for the occasional bursts of hot weather that can strike during the summer months. Researchers writing in BioMed Central's ...

Heat acclimation benefits athletic performance

Oct 25, 2010

Turning up the heat might be the best thing for athletes competing in cool weather, according to a new study by human physiology researchers at the University of Oregon.

Recommended for you

Study examines effect of hospital switch to for-profit status

23 minutes ago

Hospital conversion from nonprofit to for-profit status in the 2000s was associated with better subsequent financial health but had no relationship to the quality of care delivered, mortality rates, or the proportion of poor ...

Hospital acquisitions leading to increased patient costs

23 minutes ago

The trend of hospitals consolidating medical groups and physician practices in an effort to improve the coordination of patient care is backfiring and increasing the cost of patient care, according to a new study led by the ...

User comments