Having a cold shower in the heatwave could lead to a heart attack.
Extreme athlete Wim Hof is an advocate for cold showers, expounding their apparent numerous health benefits. And during a heatwave, one thing a lot of people want to do is take a cold shower. But is it really good for you?
This habit seemingly comes at a risk. As reported by The Conversation, having a cold shower sets off the flight-or-fight response which increases heart rate and blood pressure. This is a risk for those with heart disease as it could lead to heart rhythm irregularities or a heart attack.
Leads to two conflicting bodily responses
However, a new study by researchers at Portsmouth University has found that plunging into cold water during hot weather can cause heart attacks even in young, fit and healthy individuals, as reported by Heart.
The research follows the deaths of several people who died after going into water during the recent heatwave, however, the cause of these deaths is still unknown.
Scientists are warning that suddenly entering cold water, without taking time to adjust, may result in abnormal heart rhythms that can be fatal. The research, published in the Journal of Physiology, shows how rapid submersion in cold water, combined with holding one's breath, can affect the heart.
First, the body's cold shock response speeds up the heart rate, resulting in hyperventilation. This can then conflict with the 'diving response,' which slows down the heart rate and acts to conserve oxygen. In turn, this can cause what is known as 'autonomic conflict', resulting in heart rhythm irregularities and sometimes, sudden death.
Proceed with caution
Professor Mike Tipton, who runs the Extreme Environments Laboratory at the University of Portsmouth, said:
The body's responses to immersion in cold water are profound, uncontrollable and can result in drowning and heart problems within seconds.
The prevalence of heart problems on immersion in water tends to be underestimated because electrical disturbances to the heart are undetectable post-mortem.
The incapacitation caused by cardiac arrest, such as gasping for breath and breathing in water, means that death is often ascribed to drowning, but we believe a significant number of these cases could have a basis in autonomic conflict.
Professor Tipton recommended:
Those wanting to enter the water should do so in a slow and controlled fashion to minimise these hazardous responses.
According to a spokesperson for the University of Portsmouth, immersion-related deaths are the second most common cause of accidental death in the UK.
While it may sound counter-productive if you really want to cool down during a heatwave, try taking a hot bath.