It usually starts small. A wave of dizziness on a hot afternoon, a bit of nausea, a cramp in the calf, a strange weakness that a cold drink should fix but does not. On a brutal day, in a poorly ventilated room or out in the sun, those small signs are your body telling you it is losing a fight it works hard to win. Heat is a real health risk, and it can turn into an emergency, especially for people who work outdoors.
Extreme heat forces your body to work harder to stay cool. Sweating and blood flow to the skin release heat. When the air is very hot, humid or badly ventilated, those systems can fall behind. Dehydration sets in. Heat can also worsen heart, lung and kidney conditions that were quietly under control.
There are two stages worth recognising. Heat exhaustion brings heavy sweating, weakness, dizziness, headache, nausea, cramps or fainting. If someone shows these signs, move them to a cooler place, let them rest, and give fluids if they are awake and able to drink. Heatstroke is the dangerous stage. Confusion, collapse, seizures, a very high body temperature, or hot skin are warning signs, and heatstroke needs urgent medical help.
Some people face higher risk. Outdoor workers, older adults, children, pregnant people and people with chronic health conditions. So do people on certain medicines, including some drugs for blood pressure, fluid retention, diabetes or mental health. If that is you, ask your prescribing doctor how heat might affect your medicine. Do not stop any medicine on your own.
This is a public-health issue, not just personal bad luck. Research from India has linked heat exposure with more illness and more hospital admissions. An India-focused review describes effects on heart and lung health, mental health and the ability to work. For people who cannot choose where or when they work, heat is a serious occupational hazard.
Practical action makes a difference. Start drinking water early, before you feel thirsty. Wear light, loose clothing. Avoid heavy work during the hottest hours where you can. Employers should provide drinking water, shaded rest areas and regular breaks. Easing into work during the first hot days helps the body adapt. Never leave a child, an older person or an animal in a parked vehicle.
Neighbourhoods can prepare together, too. Check on older neighbours who live alone. Help people reach cooling centres or shaded public spaces where they exist. Schools and sports clubs can shift activity to cooler hours. Heat plans work best when they are set up before the alert, not after someone collapses.