Suture America

Hi everyone! With summer in full swing, the team here at Suture America is staying active while also taking precautions to avoid the heat whenever possible. We’ve spent time talking to students and wanted to share some information about popular questions and what you can do to beat the heat! Enjoy the read!

Heat, Dehydration, & Kidney Health in the Valley of the Sun

Temperatures in Arizona have been consistently rising from summer to summer. A city like Phoenix typically experiences over two months of 110-degree days in a typical summer. The heat is obvious, even on campus, as students walk from class to class, ducking under patches of shade and holding cold bottles of water.

The desert climate in Arizona places cities at an unusually high risk for heat-related illnesses, such as heat exhaustion or heat stroke. These devastating conditions have real effects, as a Maricopa County report makes obvious with its record-breaking number of 645 heat-related deaths in 2023. These incidents highlight the importance of understanding heat-related illnesses for the general public and healthcare professionals.

Q: What are Common Heat-Related Incidents in Arizona?

Heat cramps are one of the most common heat-related incidents, characterized by muscle spasms caused by a loss of electrolytes and fluids, typically in the form of sweat, as the body uses evaporation cooling to dissipate heat. This sweat, however, contains crucial electrolytes such as sodium, potassium, and chloride, which, when not replenished, can cause painful muscle spasms, usually in the legs, arms, or abdomen.

Heat exhaustion is a more severe stage that follows heat cramps. The body cannot cool itself fast enough through sweat, and the core temperature rises to over 101 degrees Fahrenheit. This temperature increase results in vasodilation, which can slow blood flow, thereby preventing organs and muscles from receiving adequate oxygen. Once this stage has been reached, symptoms such as a rapid pulse, nausea, and syncope will be present (Mayo Clinic, 2023).

Heat stroke: This is the most severe form of a heat-related illness. Heat stroke can have a sudden onset from intense physical activity in hot environments, or it can develop gradually from passive exposure to heat, typically in older adults and those with impaired homeostatic systems, which results in a lack of sweat production. As this progresses, vital organs, such as the kidneys, fail due to dehydration and lack of blood flow. The brain can begin to swell due to a lack of oxygen, leading to an altered mental status. A core temperature over 104 degrees Fahrenheit is a typical sign of heat stroke and should be addressed immediately.

Q: How Can I Stay Safe in the Heat?

One of the first lines of defense against a heat-related incident is hydration. Drinking water in a high-heat environment is essential, even if you do not feel thirsty (Centers for Disease Control and Prevention, 2017). On campus, familiarize yourself with refill stations and water fountains. Other electrolyte drinks are also beneficial, as electrolytes are depleted when you sweat, and these drinks provide a convenient way to replenish them.

Wearing loose and light-colored clothing can also be helpful in these environments, along with sunglasses and hats to help protect against direct sunlight. Timing your outdoor activities is also significant in reducing your risk of an incident. During the summer, the hottest part of the day is usually between 10 am and 4 pm, so time outside should be limited, with an emphasis on the morning or evening parts of the day. This is crucial when planning study sessions or breaks outside, as these seemingly harmless activities can put you at a heightened risk for an incident.

Q: Which of Our Body’s Organs are Stressed the Most During Heat Episodes?

In a heat-related episode, the kidneys are one of the most affected organs. Heat stress and dehydration cause a drop in fluid and blood volume, activating the Renin-Angiotensin-Aldosterone System and Vasopressin. As Chapman et al. (2023) describe the pathophysiology of this system, which leads to the release of renin, resulting in the production of angiotensin II and aldosterone. These hormones work together to increase sodium and water retention, as well as blood pressure, to help counteract the effects of dehydration. This cascade also results in global vasoconstriction among vascular tissues, including the renal afferent and efferent arterioles. Prolonged dehydration can harm the kidneys, as vasoconstriction reduces blood circulation to the renal tubules, which may eventually become ischemic due to prolonged hypoperfusion. This results in severe structural damage inside the kidney, where tubular epithelial cells become hypoxic during times of severe dehydration and heat stroke. The hormone Vasopressin (also known as ADH) is also triggered under dehydration status, promoting the localization of water channels in the collecting ducts of the kidney that aid in water reabsorption. These systems discussed above ultimately lead to decreased urine output and increased urine concentrations. Consequently, patients are at a higher risk for developing acute kidney injury, kidney stones, and urinary tract infections as a result (NKF).