Simultaneous heatwaves across the Middle East and North America are pushing temperatures to dangerous extremes—above 50°C in parts of Iran and past 38°C for days on end in US cities—triggering a dual crisis of public health and household energy costs. Emergency departments in Iran report a sharp increase in cases of dehydration, heat exhaustion and life-threatening heatstroke, while American utilities brace for record summer demand as air-conditioning units run at full capacity.

The human body sheds heat primarily through sweating, but in high humidity or prolonged exposure, fluid and electrolyte loss can outpace replacement, leading to a cascade from dizziness and low blood pressure to organ damage when core temperature exceeds 40°C. Those with cardiovascular, respiratory or kidney conditions are especially vulnerable, as heat forces the heart to work harder and dehydration impairs renal function. At the same time, the very technology used to escape the heat—air conditioning—introduces its own set of physiological irritations. British general practitioners note that prolonged exposure to dry, cooled air strips moisture from skin, eyes and mucous membranes, potentially aggravating eczema, triggering migraines in susceptible individuals and, if units are poorly maintained, circulating mould and dust that can provoke asthma attacks. A separate strand of advice from Iranian traditional medicine holds that drinking ice water is harmless for most, though modern clinicians caution that gulping very cold liquids after extreme heat may rarely stimulate the vagus nerve, causing a temporary drop in heart rate or blood pressure.

The financial strain of round-the-clock cooling is prompting a search for efficiency. US cooling specialists recommend raising thermostats by just two to three degrees, a change that can trim monthly bills by up to three per cent, and investing in smart thermostats that adjust temperatures when homes are empty. In the UAE, where many renters cannot make permanent modifications, portable evaporative coolers and thermal blackout curtains are gaining traction as low-cost ways to block solar heat gain before it enters living spaces. Government-backed Energy Star ratings provide a benchmark for those upgrading window units or central systems, with newer models using significantly less electricity to deliver the same cooling output.

The immediate test will arrive as the Gulf region moves into its peak humidity period in August, when the combination of heat and moisture strains both the body’s ability to cool itself through sweat and the efficiency of evaporative cooling devices. Health ministries across affected countries are updating heat-health action plans, urging citizens to recognise the warning signs of heatstroke—confusion, hot dry skin, and loss of consciousness—and to seek emergency care without delay.