A minor heat-induced illness can look like heat cramps, heat edema (swelling) or heat rash, as well as syncope (passing out) or tachycardia (elevated heart rate over 100 beats per minute).

heat edema and heat stroke. Heat combined with high humidity exacerbates this risk, since the air’s saturation level makes sweat accumulate on the skin, preventing the body from cooling naturally.

“Ankle swelling in the heat is simply your body’s physiological reaction to the heat and trying to keep our bodies at a nice steady temperature,” says Dr Zoe Watson, GP and founder of ...