A fever, defined as a temporary rise in body temperature to 100.4°F (38°C) or higher, signals that the body’s immune system is actively fighting an infection. While cooling off in the water may be appealing, swimming with an elevated temperature is generally ill-advised. This decision involves considering the physiological stress on your body, the risk of spreading the illness to others, and the safety hazards posed by fever symptoms.
How Swimming Affects Your Body’s Fight Against Infection
A fever is a metabolically demanding process, increasing the body’s energy expenditure to fight off pathogens. The physical exertion of swimming diverts valuable energy away from the immune system toward muscle activity. This additional strain can suppress the immune response, potentially prolonging the illness or worsening symptoms.
Strenuous activity while the body is already compromised can also increase the risk of more serious complications. In cases where a viral infection is present, exercising with a fever has been linked to an increased risk of myocarditis, which is inflammation of the heart muscle. This condition can disrupt the heart’s electrical system and pumping ability, creating a potentially life-threatening situation.
The body’s thermoregulation is challenged by the fever itself, and immersion in water adds complexity. Water transfers heat much more efficiently than air, forcing the body to work harder to maintain its core temperature. This further taxes a system already struggling to regulate internal heat. Fever also increases fluid loss, and dehydration combined with physical activity leads to greater systemic stress and delayed recovery.
Contagion Concerns in Public Water Settings
Choosing to swim in a public setting when feverish presents a significant public health risk due to the potential for pathogen transmission. For gastrointestinal illnesses that often cause fever, waterborne pathogens like Cryptosporidium, Giardia, and E. coli are shed in the feces of an infected individual. These pathogens can contaminate the water, and while chlorine kills many germs, some, such as Cryptosporidium, are highly chlorine-tolerant and can survive for days.
Respiratory illnesses, such as the flu or a common cold, are not typically spread through the water itself but through respiratory droplets. Coughing, sneezing, or blowing the nose on the pool deck, or using shared surfaces like railings and locker room benches, can easily transmit viruses. The air quality in poorly ventilated indoor pools can also be a factor, as volatile chloramines irritate the respiratory systems of other patrons.
Assessing Immediate Safety Risks
Fever is frequently accompanied by symptoms that directly impair physical coordination and mental clarity, dramatically increasing the risk of accidents in a water environment. Symptoms such as lightheadedness, dizziness, and general weakness are common manifestations of a body fighting infection. These impairments can lead to an increased likelihood of slipping on the pool deck or experiencing a sudden bout of disorientation while in the water.
Dehydration, often a consequence of fever and increased fluid loss, further contributes to feelings of fatigue and confusion, which can compromise the ability to swim safely or react quickly in an emergency. Furthermore, many over-the-counter fever-reducing medications contain ingredients that can cause drowsiness or blurred vision. Engaging in an activity like swimming while under the influence of these symptoms or medications increases the acute risk of injury or drowning, making staying out of the water the safest choice.