Ask the doctor: Hot tubs and heart health
Q. Is it safe to sit in a hot tub if I have a heart condition? The signs above hot tubs say older people and people with heart disease should check with their doctors.
A. Soaking in a hot tub can increase your heart rate and lower your blood pressure. This explains the ubiquitous signs posted near hot tubs warning heart patients to consult their doctors before entering. Indeed, it is prudent to ask your doctor if a sudden increase in heart rate (about equivalent to moderate physical activity) could be risky for you. In addition, a drop in blood pressure (up to 20 mm Hg in systolic blood pressure) could trigger lightheadedness or even fainting in a susceptible individual.
As you might imagine, few scientific studies have examined the safety of hot tubs for people with heart conditions. Despite the widespread use of hot tubs, there are no convincing reports that soaking in hot water leads to heart attacks or heart failure.