Health Library / Seasonal & local
Lucknow summers: dehydration, electrolytes and who is most at risk
· 5 min read · Lucknow
Lucknow summers run hot for months, and heat illness is one of the more preventable causes of serious harm each year. It builds gradually — through dehydration and salt loss — and then turns dangerous quickly.
Knowing the difference between heat exhaustion, which you manage, and heat stroke, which is a medical emergency, is genuinely worth having in your head before you need it.
Exhaustion versus stroke
Heat exhaustion involves heavy sweating, weakness, headache, nausea, dizziness, cramps and a fast pulse. The person is uncomfortable and unwell, but mentally clear. Move them somewhere cool, lie them down, cool them, and give fluids with some salt.
Heat stroke is different in kind, not just degree. Body temperature climbs above roughly 40°C and mental state changes — confusion, slurred speech, agitation, seizures or unconsciousness. Sweating may have stopped and the skin can be hot and dry. This is an emergency: call for help, move them into shade, cool them aggressively with water and airflow, and get them to hospital. Do not wait to see whether it settles.
- Confusion, slurred speech or unusual behaviour in the heat
- Very high temperature, with hot skin that may be dry
- Seizure or loss of consciousness
- Repeated vomiting, or inability to keep fluids down
- No urine passed for many hours
Which tests matter
For significant dehydration or heat illness the relevant tests are serum electrolytes — sodium and potassium in particular — along with kidney function, because dehydration puts the kidneys under strain and severe cases can cause acute kidney injury.
In heat stroke, doctors also check muscle breakdown markers, liver enzymes and clotting, since severe heat illness affects multiple systems. That is inpatient territory, not something to arrange yourself.
For ordinary summer tiredness the more useful panel is often the boring one: a CBC for anaemia, thyroid function, and sugars. Fatigue that persists once the heat passes usually has another explanation.
Who to watch, and how to prevent it
Older adults feel thirst less reliably and are on more medicines that affect fluid balance — diuretics especially. Infants and small children dehydrate faster. Outdoor workers, anyone with heart, kidney or lung disease, and people on certain psychiatric medications are all at higher risk.
Prevention is unglamorous and effective: drink through the day rather than waiting for thirst, avoid the peak afternoon hours outdoors, use ORS or salted lemon water when sweating heavily, wear light loose clothing, and check on elderly neighbours and relatives during a heatwave. Plain water alone is not always enough when salt losses are heavy.
This article is general health information, not a diagnosis or a treatment plan. Test results are read alongside your symptoms and history — please discuss yours with your doctor. See our disclaimer.
