Sweating in a Dubai summer: what your body is actually doing

This distinction is the whole story. Liquid sitting on your skin removes almost no heat. Heat leaves the body only when that liquid changes into vapour, a process that consumes a large amount of energy and takes it from you. Sweat that runs off, drips, or is wiped away has cost you fluid and salt and delivered nothing in return.

Evaporation depends on the surrounding air having room to accept more water. When humidity is high, as it is along this coast through late summer, the air is already close to saturated. Sweat therefore lingers on the skin instead of vaporising. Your body reads the continuing rise in core temperature and responds the only way it knows: by producing more sweat. Hence the familiar August experience of being drenched and still hot.

It also explains why moving air helps so much more than it seems it should. A fan does not lower the temperature of a room by any meaningful amount; it replaces the saturated layer of air against your skin with drier air, and evaporation resumes.

People who arrive in Dubai in summer often notice that they sweat more heavily after two or three weeks than they did on arrival, and conclude that something is wrong. The opposite is true.

Heat acclimatisation is a genuine physiological adaptation that develops over roughly one to two weeks of repeated exposure. The body learns to start sweating at a lower core temperature, to sweat more readily, and to conserve salt while doing it, so the sweat becomes more dilute. The result is a cooling system that engages earlier and wastes less. It feels like sweating more because it is sweating more, and that is the adaptation working.

Acclimatisation is also lost, over a similar timescale, when exposure stops. A summer spent moving between cooled buildings and cooled cars provides very little of it, which is part of why an unexpected twenty minutes outdoors in August feels so punishing to residents who spend the season indoors.

A specific local pattern: you step out of a strongly cooled building into the outdoor air and within moments you are sweating heavily, often more than the walk itself justifies. There is nothing abnormal in this. Your skin vessels were constricted in the cold interior, your body was in heat-conserving mode, and the sudden load triggers an abrupt correction. Give it a few minutes and it settles.

The same transition is what defeats antiperspirants for many people in summer. Applied in the morning, over skin that is already damp, immediately before a heat load, the product never gets the dry, low-sweat window it needs to form a plug in the duct. Applying it at night, to fully dry skin, is not a minor detail. For a lot of people it is the difference between the product working and not.

Summer makes this harder to judge, because everyone around you is sweating too. Three questions usually settle it.

Heavy sweating in heat is normal. Heat illness is not, and it sits on a spectrum that can escalate quickly. Heat exhaustion tends to involve heavy sweating with cool, clammy skin, weakness, dizziness, nausea, headache and cramps. The response is to move somewhere cool immediately, lie down, loosen clothing, sip fluids and cool the skin.

The dangerous turn is counter-intuitive. In heat stroke the skin may become hot and dry and sweating may stop, because the regulating system has failed rather than succeeded. Confusion, agitation, slurred speech, a pounding headache, a very high temperature, collapse or loss of consciousness are emergency signs. This is a call-for-help situation, not a rest-and-see one.

Older adults, young children, people working outdoors, people with heart or kidney conditions and anyone taking medication that affects fluid balance or sweating carry more risk and should treat the summer with correspondingly more caution.

July is when people notice the problem, which is not the same as when it is easiest to solve. Topical measures can begin tonight and are worth getting right before anything else is considered. Treatments that interrupt the nerve signal take days to begin and a couple of weeks to develop fully, so they reward planning.

The practical implication for anyone in the middle of a Gulf summer is simple enough: treatment now still helps the rest of the season, and an appointment in spring covers the season from its start rather than its middle. Both are reasonable, and it is worth knowing which one you are choosing.