MISSISSIPPI STATE -- Heat and humidity make it uncomfortable to work or play strenuously outside during Mississippi summers, but the high temperatures can be more than an inconvenience.

Jane Clary, health specialist with the Mississippi State University Extension Service, said heat exhaustion, heat stroke, also known as sun stroke, and heat cramps are all caused by physical exertion without adequate hydration. All are caused when the body fails to cool itself adequately. While most common in the summer, they can occur in cold weather, too.

“Because of the heat and high humidity of our state, those working or playing outside should take extra precautions to avoid heat illnesses,” Clary said.

Online authority http://webmd.com says that heat illnesses such as heat exhaustion, heat cramps and heat stroke are caused by prolonged or intense exposure to hot temperatures.

“As your body works to cool itself under extreme or prolonged heat, blood rushes to the surface of your skin. As a result, less blood reaches your brain, muscles and other organs,” the medical site says. “This can interfere with both your physical strength and your mental capacity, leading, in some cases, to serious danger.”

Symptoms of heat exhaustion include headache, nausea or vomiting, sweaty skin, weakness, a rapid pulse, dizziness, dehydration and possible disorientation. To treat a person with heat exhaustion, take them to air conditioning or a shady area, increase their fluid intake with water or sports drinks, and cool their body with fans or towels soaked in ice water.

Heat stroke is more serious, and symptoms include a high body temperature, hot and dry skin, a weak pulse and a loss of consciousness. This is an emergency situation that should be treated by trained professionals who will decrease the body temperature, monitor vital signs and take the person to the emergency room.

Heat cramps is a more common heat illness and is often experienced by those working or training hard outside.

“A person can get heat cramps when the body depletes fluids faster than it can replace them. Cells become dehydrated and lose their electrolytes, which results in muscle cramping, usually starting in the calves or hamstrings,” Clary said.

Children are at a particular risk of heat illnesses because their bodies can not yet cool themselves efficiently and they do not know the importance of staying hydrated.

MSU associate athletic trainer Jay Logan works with the baseball team to keep them fit and injury-free. He said nearly all heat illnesses are preventable with the right information and plenty of fluids.

“The best way to prevent heat illnesses is to drink the right kinds of fluids before, during and after any kind of activity,” Logan said. “The body cools itself by sweating, so replace the fluids you use and keep your body's air conditioner working.”

Logan said people need plenty of fluids when outside during the summer. Water and sports drinks are excellent fluids to drink while exercising or working in the heat, while soft drinks, alcohol and fruit juices are not recommended.

“Drinking the right kinds of fluids is just as important as having the right kind of equipment for doing your sport,” Logan said.

In addition to drinking plenty of the right fluids, those working or exercising in the heat should allow themselves time to acclimate to the conditions and wear light-colored, loose-fitting, breathable clothing and a hat.

“If you have a headache or feel bad at the end of the day, you probably didn't keep yourself hydrated,” Logan said.

Logan encouraged everyone outside in the heat to drink plenty of fluids and stay alert to symptoms of heat illness.