The Indian Meteorological Department issued a severe heat wave warning for North and Central India on Thursday. Given the record-breaking temperatures seen in the country this week, the warning is necessary.
But what kind of impact does extreme heat have on the human body, especially on those who are continuously exposed to it?
In normal heat conditions, the body cools down by sweating. But sometimes sweating is not enough or not possible (for instance, if the person is dehydrated). In such cases the temperature of the body rises rapidly, which may damage the brain and other vital organs such as the brain, kidneys and the liver.
Old people and children are most vulnerable to this condition. People on certain medications, especially those with high blood pressure, who are advised diuretic medicines (or urine-producing medicines as they are colloquially referred to) to remove the excess water from the body (which in turn reduces salts) are also vulnerable.
People affected by extreme heat can suffer in three stages of increasing severity:
Heat cramps
When a person is exposed to heat, the electrolyte balance in the body is affected due to excessive sweating. This early stage is called heat cramps, in which people feel painful cramps in legs and abdomen. This is why the standard advice given to people during the summer is to drink a lot of water. “It is better if people add salt, sugar and some lemon juice in the water to restore the electrolyte imbalance,” said Dr RP Agarawal, professor and head of medicine, Sardar Patel Medical College, Bikaner, Rajasthan.
Heat exhaustion
Those continuously exposed to heat, who are unable to replace the water and electrolytes in the body that they are losing through sweat, will suffer from heat exhaustion. The body could reach a stage where circulation of blood to the brain reduces. Apart from cramps, those suffering from heat exhaustion may experience nausea, dizziness or blurred vision. They may feel slightly disoriented, and may be unable to continue their activities as a result. Many even faint.
Heat stroke
Left untreated, heat exhaustion can proceed to heat stroke, a life-threatening condition. When the sweat glands are exhausted and are not able to produce any more sweat because of excessive heat and the lack of water, the body temperature rises sharply. “When there is no fluid to cool the body, the internal defence becomes weak and the core temperature increases,” said Dr Agarawal. “When it [body temperature] reaches about 105 degrees Celsius, we call it a heat stroke,”
The usual mode of treatment for anyone suffering from heat stroke is to bring down their body temperature urgently. They are made to sit in an air conditioned room (such rooms are assigned in some hospitals and district hospitals in the country), or a cooler room, or are given sponge baths. “We also spray water with an exhaust fan on the patient,” said Dr Agarwal. “Also, the saline we give the patient is cold. Occasionally we also massage the body with ice cubes. If the patient comes soon enough, we can save his or her life.”
If there is a delay in cooling down those who have suffered from a heat stroke, he or she can suffer brain haemorrhage and respiration distress. This could lead to delirium, seizures or coma, and is a potentially fatal condition.
“The organs of the body start collapsing because the tissues of the body cannot function in extreme heat,” said Dr Mamta Manglani, head of paediatrics, Lokmanya Tilak General Hospital, Mumbai. “It can lead to renal and liver failure too.”
