Millions of Americans look forward to hopping into a hot shower to wash off the grime of a long day and ease tired muscles. 

In fact, a recent Harris Poll found just over half of US adults prefer warm showers, while 17 percent crank the heat up as high as they can handle. 

The occasional blistering hot shower is likely harmless, but experts have warned consistently turning up the heat may raise the risk of heart disease, cardiac arrest and stroke.

Exposure to hot water widens the blood vessels, a process known as vasodilation, to push warm blood to the skin’s surface. 

At the same time, blood pressure plummets, so the heart is forced to pump faster to maintain blood flow. 

In fact, recent studies suggest hot showers may spike heart rate by over 30 percent.

‘When the body is exposed to very hot water, blood vessels near the skin begin to dilate in an effort to release heat and regulate body temperature,’ Dr Xzabia Caliste, vascular surgeon at Albany Med Health System in New York and Society for Vascular Surgery Ambassador, told the Daily Mail.

‘That shift redirects blood flow toward the skin, and in response, the heart often works harder and beats faster to maintain adequate circulation and blood pressure throughout the body.’

While hot showers can ease tired muscles, doctors have warned they may strain the heart over time (stock image)

The heart rate spikes and blood pressure dips can lead to dizziness, especially in people with pre-existing heart conditions, raising the risk of fainting and sustaining a head injury. 

And consistent episodes of high heart rate place strain on the heart, forcing the organ to work harder and depriving it of oxygen-rich blood, eventually raising the risk of a heart attack. 

One 2021 study looked at 10 healthy men ranging from their 20s to 50s. The researchers found hot water raised participants’ heart rates by 32 percent on average.

The amount of blood their hearts pumped with each beat also jumped 44 percent. This is a sign of increased cardiac output, or the heart pumping more forcefully. 

While many healthy people can sustain higher heart rates and lower blood pressure, these fluctuations can be dangerous for those with pre-existing conditions. 

Dysautonomia, an umbrella term for conditions that cause malfunctions in the autonomic nervous system, causes severe fluctuations in blood pressure from minor changes like going from sitting to standing. 

Those fluctuations, coupled with blood pressure dips from a hot shower, raise the risk of lightheadedness, blurry vision and fainting. 

‘In healthy individuals, the body usually compensates quickly, but for some patients, like those with vascular or cardiovascular conditions, these changes can be more significant and result in serious issues like a heart attack or stroke,’ Caliste said.

However, Caliste cautions that ‘most people do not need to avoid warm showers,’ but certain groups should turn down the temperature.

‘Very hot or prolonged showers should be used cautiously by older adults, individuals with heart disease, vascular disease, low blood pressure, or poor circulation due to the potential cardiovascular stress,’ she said.

‘Patients who are dehydrated, taking blood pressure medications, or prone to dizziness and falls should also be cautious, as sudden vascular changes can increase the risk of fainting or instability.’

Health experts typically recommend a shower temperature between 98F and 105F to reduce the risk not only of circulation issues but skin damage, as hot temperatures can strip away protective barriers and increase the risk of eczema and redness.