Sunny, high pressure days are associated with better mood and greater ‘openness’, meaning people are more likely to be creative. However, while moods might be buoyant during a sunny spell, productivity takes a hit. When the weather is hot, the body becomes less efficient at dispelling heat that is created as a by-product of intense mental activity.
This effect can impact on a whole range of cognitive activities and could explain the foggy headed effects of heat. In our overheating world, it will become more difficult to say whether psychological effects are only down to the weather or simply the paralyzing acknowledgement that the world is headed for climate crisis.
Our body will strive to keep a core temperature of about 37.5C whether we’re in a heatwave. But as the mercury rises, the body has to work harder to keep its core temperature down. It opens more blood vessels near the skin to lose heat to our surroundings and starts sweating. As the sweat evaporates, it dramatically increases the heat lost from the skin.
This might sound simple but it puts a strain on the body – and the higher temperatures rise, the greater the strain. Those opened up blood vessels lead to a lower blood pressure and make the heart work harder and pump faster to push the blood around the body. This can cause mild symptoms such as an itchy heat rash or swollen feet as blood vessels become leaky.
But if the pressure drops too low, then insufficient blood will reach the organs that need it and the risk of heart attacks rises. At the same time, sweating leads to the loss of fluids and salt and, crucially, the balance between them in the body changes.
And this combined with the lowered blood pressure can lead to heat exhaustion, the symptoms of which include: • dizziness • fainting • confusion • nausea • muscle cramps • headaches • heavy sweating • tiredness
The highest temperatures will obviously be during the day, when the sun is beating down on us, but night-time temperature is also crucial. The reason is the body needs a break. If the strain of keeping the core body temperature under control continues through day and night, then it increases the risk of health problems.
The advice is pretty simple and obvious – stay cool and hydrated. One way of thinking about it is to act like you would on a hot, sunny holiday – you don’t stop having fun but you do change your behavior. Drink enough water, and don’t forget your suncreen.
Try to keep it cool, if it’s hotter outside than inside your home, then you might be better off keeping the windows closed, the curtains drawn and the feet up. Or go sit in a bath filled with icecubes while wearing your sunnies.