Heat changes the strain of the same step sequence
When you dance, your muscles produce heat. Outdoors, your body also has to cope with the surroundings: it sends more blood to your skin and releases heat, among other ways, through evaporating sweat. As a result, a familiar sequence can feel much more strenuous than it does in a cool room. Sweating a lot does not automatically mean you are cooling down enough. If sweat drips off instead of evaporating, its cooling effect is limited.
Besides air temperature, three heat factors matter: direct sunlight, humidity, and air movement. In humid, still air, sweat evaporates less easily; on a sunny meadow, radiant heat adds to the strain. That is why you cannot simply assume that your usual dancing time will work on every hot afternoon. Even a slow song can become strenuous if you cover a lot of ground or dance in deep positions the whole time. This is especially clear when you see why music tempo is not the same as difficulty.
For this afternoon, first reduce the physical effort: take smaller steps, do fewer turns, skip jump sequences, and dance for shorter stretches. A familiar variation like the Sailor Step without a turn saves you extra changes of direction without making you learn a new sequence. Still, it is not protection from the heat. What matters is that you really get out of the sun between rounds and stop as soon as you experience any symptoms. The music can keep playing even when you are already sitting down.
