Humans are not able to withstand extreme heat for long periods of time. The body responds to heat stress with gradually worsening symptoms, categorized under three heat-related illnesses that increase in severity called heat cramps, heat exhaustion and heatstroke, the latter of which occurs when the body’s heat-regulating system is overwhelmed.
The following chart is based on information from the expert medical platform Patient.info and outlines the main symptoms of heat exhaustion and heatstroke. When a person experiences heat exhaustion, the core body temperature remains at less than 40 degrees Celsius (104 degrees Fahrenheit) and is accompanied by symptoms such as mild confusion, irritability, anxiety and poor coordination. At this stage, a person’s ability to regulate their temperature is still functioning and so they will likely sweat heavily. Their pulse may be racing and they could feel nauseous, have a headache and feel suddenly faint when they stand up.
Heat exhaustion can quickly turn into the more dangerous heatstroke. In this instance, a person’s core body temperature rises above 40 degrees Celsius (104 degrees Fahrenheit) and their self-regulating system for heating and cooling the body stops working properly. This may result in them stopping sweating completely, with their skin feeling deceptively cool and dry. In serious cases of heatstroke, a person may fall into a coma or have a seizure and can experience widespread damage to their brain, liver, kidney and muscle.
According to medical experts, in both cases it is important to try and cool down the body as much as possible. This involves moving the person into a shaded area or somewhere with air conditioning, using cold water and placing ice packs behind their neck, under the armpits and in the groin area to lower their temperature. If someone has heatstroke, it is crucial that emergency help is called immediately. If they are unconscious the person needs to be moved into the recovery position and someone should wait with them until an ambulance arrives. According to South Australia Health, it is also not recommended to give a person suffering from heat stress aspirin or paracetamol.
People particularly vulnerable to the effects of intense or prolonged heat include young children, older adults, pregnant people, or those with chronic medical conditions. But socio-economic levels have an impact too, with the poorest often feeling the brunt of heatwaves first. Last week, a total of 192 homeless people in the north Indian city of New Delhi died from the heat, living without protection against the high temperatures.
