// BBC HEALTH NEWS — SALUTE
What does hot weather do to the body?
Periods of hot weather can affect anyone, but some people run a greater risk of serious harm.
Experts recommend that those who may be more vulnerable - such as older people and babies and young children - should take extra precautions.
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:
If blood pressure drops too far, the risk of heart attacks rises.
How does sunscreen work, and how much do you need to use?
Our bodies strive to keep a core temperature of about 37C whether we are in a snowstorm or a heatwave.
That is the temperature at which our bodies have evolved to work.