What does extreme heat do to our bodies?
Monday 20th July 2026
As the body gets hotter, blood vessels open up. This lowers your blood pressure and makes your heart work harder to push the blood around the body.
This process can cause mild symptoms such as an itchy heat rash or swollen feet.
At the same time, sweating leads to the loss of fluids and salt and, crucially, the balance between them in the body changes.
This, combined with the lowered blood pressure, can lead to heat exhaustion. Symptoms include:
dizziness
nausea
fainting
confusion
muscle cramps
headaches
heavy sweating
tiredness
If blood pressure drops too far, the risk of heart attacks rises.