- Heat stroke is a severe condition caused by high body temperature and heat exposure symptoms
- Heat exhaustion symptoms include dizziness, fatigue, sweating, and dehydration, needing prompt care
- Heat stroke can occur even at moderate temperatures with intense physical exertion
You feel tired, a bit dizzy, maybe a headache after a long day under the blazing sun. You brush it off as just another summer fatigue. But in the time, it takes for the temperature to climb a few more degrees, that "minor" discomfort can cross a terrifying line- into a medical emergency where your body literally begins to cook from the inside.
This silent escalation from heat exhaustion to heat stroke is claiming lives across India even as temperatures soar to 45 degrees once again. While official numbers may understate the crisis, the warning from doctors is clear: what starts as manageable can rapidly become fatal.
Heatwave to severe heatwave conditions are likely to persist over the plains of Northwest India, Central and East India, and parts of Peninsular India during the next six to seven days, the India Meteorological Department (IMD) said on Friday.
A Lethal Spectrum
Dr. Ajay Chauhan, Professor of Medicine at Dr. Ram Manohar Lohia Hospital, Delhi, and In-Charge of the hospital's Heat Stroke Unit, told NDTV about the dangerous progression: "Heat stroke is the most severe and lethal form in the spectrum of heat-related illnesses, which ranges from mild conditions like prickly heat to heat syncope, heat edema, heat exhaustion, and finally heat stroke."
He describes classic heat stroke as a clinical triad: core body temperature exceeding 105 degrees Fahrenheit (measured rectally), altered mental state ranging from aggression and delirium to coma, and a clear history of heat exposure.
Crucially, Dr. Chauhan notes that extreme ambient heat isn't always required. "It can occur even at 27-28 degrees Celsius in cases involving intense physical exertion, such as soldiers carrying heavy loads or marathon runners," he says, highlighting the deadly combination of environmental heat and the body's internal stress.
Many people in India are already showing early red flags- dizziness, fatigue, sweating, and dehydration- classic signs of heat exhaustion that can spiral quickly, especially among the vulnerable.
When The Body Loses Control
Dr. Juhee Jain, Director of Obstetrics and Gynecology at Madhukar Rainbow Children's Hospital, warns that certain groups face heightened risks. "Heat exhaustion is a serious condition caused by extreme heat. If not recognised and treated promptly, it can lead to life-threatening heat stroke. Women, especially those who are pregnant, are more susceptible during high temperatures."
She explains the physiology: excessive sweating leads to fluid and electrolyte loss, causing weakness, dizziness, nausea, rapid heartbeat, muscle cramps, and headaches. "If a person stays in high temperatures without cooling down or drinking fluids, their body loses its ability to control its internal temperature. This can result in heat stroke... A body temperature above 104 degrees Fahrenheit indicates heat stroke. Symptoms may include confusion, fainting, disorientation, hot dry skin, seizures, or even unconsciousness."
For pregnant women, the stakes are even higher, with risks of low blood pressure, reduced blood flow to the baby, and preterm contractions.
Dr. Amit Prakash Singh, Consultant in Internal Medicine at CK Birla Hospital, Delhi, adds context on how quickly things deteriorate: "Heat exhaustion is often the first warning sign that the body is struggling to cope... If a person continues to remain in the heat without proper cooling or hydration, the body's core temperature may rise dangerously, eventually triggering heat stroke."
"Unlike heat exhaustion, heat stroke affects the brain and vital organs directly," he continues. "Patients may become disoriented, aggressive, confused, or unconscious. In severe cases, it can cause multi-organ failure involving the kidneys, heart, liver, and brain."
India's Recurring Crisis
The numbers paint a grim picture. In 2024, India endured devastating heatwaves with over 40,000 suspected heatstroke cases and 110-459 confirmed deaths between March and July, according to official reports. Independent analysis by HeatWatch recorded 733 deaths across 17 states. Though 2025 saw lower official figures (7,192 suspected cases and 14 confirmed deaths by June), media reports tracked at least 84 deaths, concentrated in states like Maharashtra, Uttar Pradesh, and Telangana.
The most vulnerable remain the elderly, outdoor workers (farmers, construction labourers, gig delivery personnel), children, and those with pre-existing heart, lung, or kidney conditions. Poor housing, lack of access to cooling, and long hours in the sun compound the danger. Underreporting means the real toll is likely much higher.
Prevention: Simple Steps, Serious Stakes
All three doctors emphasize that early intervention can save lives.
"Drinking adequate water, avoiding outdoor exposure during peak afternoon hours (especially 12-4 pm), wearing loose cotton clothing, and recognising early warning signs can significantly reduce the chances," says Dr. Singh.
Dr. Jain adds practical advice for at-risk groups: stay hydrated, avoid direct sun during the hottest hours, and seek medical help immediately if symptoms worsen.
Disclaimer: This content including advice provides generic information only. It is in no way a substitute for a qualified medical opinion. Always consult a specialist or your own doctor for more information. NDTV does not claim responsibility for this information.
