Physiological Hazards Resulting From Heat

The Body can dissipate heat only through evaporation of sweat.When heat loss due to due to evaporation is unable to cop up with the heat gain,there will be storage of heat in the body and the temperature of the body rises.Several physiological hazards exist,the severity of which depends upon the extend of time duration of body temperature rise.Following are some of the physiological hazards.

1.Heat Exhaustion :   It is due to the failure of normal blood circulation.The symptoms include fatigue,headache,dizziness,vomiting and irritability.It does not cause permanent injury to the body and recovery is usually rapid when the person is moved to a cool place.

2.Heat Cramp :  It results from loss of salt due to excessive rate of body perspiration. It causes severe pain in the calf  and thigh muscles.The heat cramps can be avoided by using salt tablets.

3.Heat stroke :  It is the most serious hazard.When a man is exposed to excessive heat the and work ,the body temperature may rise rapidly to 40.5 deg (105 F )or higher . At such elevated temperatures sweating ceases and the man may enter a comma, with death imminent. A person experiencing a heat stroke may be avoided by taking sufficient water at frequent intervals.It has been found that a man doing hard work in the sun requires about one litre of water per hour.