Many parts of North India are reeling under intense heat, with temperatures hitting record highs.

The scorching heat being witnessed in parts of India due to emissions and global warming is not just a rise in temperature, but a persistent heatwave throughout the day and night.

As temperatures rise, the human body’s endurance is tested, and not surprisingly, it begins to weaken. Dehydration sets in.

To cool the body, we sweat, losing precious water and electrolytes. Skin becomes dry, lips crack, and bone-deep fatigue sets in. Muscles cramp, the pulse quickens, and the mind becomes dizzy.

This is a cry for help, indicating that the balance of life-sustaining fluids needs immediate attention.

This is what happens to the body during a heat wave, and hydration is key to avoiding it.

What is a heatwave?

A heatwave is a prolonged period of extremely hot weather, which may be accompanied by high humidity, particularly in countries with oceanic climates.

The exact definition of a heatwave can vary by region, but generally involves temperatures significantly above the average maximum temperature for a specific location during a particular time of year.

This summer, the India Meteorological Department (IMD) has issued severe heat wave warnings for several regions of the country, including Delhi, Odisha, Andhra Pradesh, Telangana, West Bengal, Uttar Pradesh and parts of Karnataka.

The temperature ranged from 41 degrees Celsius to 50 degrees Celsius. Scientifically, the maximum temperature at which the human body can function properly is 42.3 degrees Celsius.

When the body undergoes extreme heat conditions, the first sign of heatstroke or heat stress is dehydration.

Heat stress occurs when the body is exposed to excessive heat, which can impair its ability to regulate temperature and maintain normal functioning. It leads to heat exhaustion such as muscle cramps, sweating, dizziness, nausea and clammy skin, and in the worst cases, it can lead to heat stroke (fainting), where immediate attention is required.

Heat stroke can occur at 40°C if the body is dehydrated. In severe cases, it can even lead to organ failure.

What happens during dehydration?

According to Dr Honey Savla, Internal Medicine, Wockhardt Hospitals, Mumbai, during a heatwave, you can lose large amounts of water and essential electrolytes (sodium, potassium, magnesium) in a short period of time, and if fluid intake is inadequate, severe dehydration can occur within a few hours.

“Mild dehydration causes thirst, dry mouth, decreased urination, dark yellow urine and dry skin,” the expert said.

Moderate dehydration further intensifies these symptoms, resulting in very dry mouth and mucous membranes, significantly decreased urine output (less than 400-500 ml/day), dark colored urine, rapid heartbeat, weakness, fatigue, dizziness, and lightheadedness.”

Severe dehydration can be life-threatening, with symptoms including extreme thirst, little or no urination, very dry skin and mucous membranes, rapid breathing and heart rate, low blood pressure, confusion, irritability, sunken eyes, and in severe cases, unconsciousness or organ failure.

Strategies to hydrate the body

Water is the best way to keep the body hydrated during summer, yet due to excessive sweating the body loses essential electrolytes, which cannot be replaced by water.

However, drinking water at certain times may be sufficient for the body. According to the US Centers for Disease Control and Prevention (CDC), drinking water at the beginning of work makes it easier to stay hydrated throughout the day.

According to the CDC, “drink water before you feel thirsty.”

“By the time you feel thirsty, you’re already past fluid loss. Dehydration is the leading cause of heat exhaustion,” say CDC experts. To stay hydrated, drink a cup of water (230 ml) every 15 to 20 minutes. This prevents thirst and regulates the body’s fluid function.

Drinking water at smaller intervals is more effective than drinking large amounts of water occasionally.

The CDC further states, “Do not drink more than 1.5 liters of water per hour. Drinking too much water or other fluids (sports drinks, energy drinks, etc.) can cause a medical emergency because the salt concentration in the blood may drop too low.”

There is not enough water

Dr Mohan Kumar Singh, Senior Consultant, Internal Medicine, Marengo Asia Hospital, Gurugram, said that if you drink only water during the scorching heat, you are at risk of getting severely dehydrated.

“Heat waves can worsen dehydration due to increased sweating and evaporative water loss. When the body loses more fluids than it takes in, the body becomes dehydrated, which can have dangerous effects and disrupt vital bodily processes,” Dr Singh said.

Dr. Savla said that apart from water, electrolyte-rich fluids such as sports drinks and oral rehydration solution (ORS) can help replace lost electrolytes and fluids.

However, look for ORS packets that say “WHO-approved.”

“Consuming hydrating foods such as coconut water, cucumbers, watermelon, oranges, strawberries, seasonal fruits and green leafy vegetables can help with hydration. Soups and broths provide both fluids and electrolytes,” said Dr. Savla.

Avoid alcohol and caffeine to maintain hydration.

Another strategy to reduce the risk of dehydration is to wear light and loose clothing, Dr. Singh said.

Using fans or air conditioning indoors and taking periodic breaks from outdoor activities can help prevent heat-related illnesses and help you stay hydrated.

Drinking water alone will not keep you hydrated enough during the summer. During the scorching heat, protect yourself from dehydration and related health problems by replenishing electrolytes, eating hydrating foods, and minimizing water loss.