For millions living in the US, the summer heat has been both relentless and devastating. According to the American Red Cross, some states’ temperatures are reaching new record-high numbers, even reaching 30 degrees above the normal numbers for this time of the year. The heat’s been so extreme that it’s even affecting radio signals and causing communication interference in places under heat domes.

The high temperatures and humidity levels have also prompted public warnings in several states to stay indoors to reduce the risk of potentially life-threatening conditions. The triple-digit temperatures are especially dangerous for individuals living with chronic illnesses, such as those with diabetes, who are more prone to dehydration or may not be able to cool down their bodies’ internal temperatures as effectively due to complications associated with the illness. Studies show that extreme temperatures and high humidity can cause a surge of diabetic patients visiting the ER.

In this article, we discuss why heat increases ER visits for diabetic patients. We also tackle the warning signs that diabetic patients should watch for to help them manage their illness during extremely hot weather.

The Research: How Extreme Heat Drives Diabetes-Related ED Visits

Those living with chronic illnesses, including diabetes, heart disease, and kidney disease, as well as those with advanced ages, are at an increased risk of heat-related fatalities, which is why emergency department visits surge when temperatures surge. Extreme heat diabetes emergency department visits research shows that rising temperatures can place additional strain on vulnerable patients and healthcare systems.

When temperatures are high, research shows that people tend to consume more sugary drinks and frozen treats to quell the heat. A 2025 study finds that because of the extreme heat brought about by global warming, Americans consume more than 100 million pounds of added sugar in a year compared to the amount they consumed 15 years earlier. Although people living with diabetes can have sweets at well-managed levels, too much sugar can cause a spike in blood sugar levels, making it harder to manage diabetes and increasing the risk of developing diabetes-related complications.

The extreme heat also affects the hydration levels of people living with diabetes. Heat can increase the risk of dehydration, which could then lead to an increase in a person’s blood sugar levels. Dehydration reduces the amount of water present in a person’s bloodstream, which creates a higher concentration of glucose. High temperatures can also affect how insulin works in the body, which would mean that people with diabetes would need to test their blood glucose levels more regularly and adjust their insulin doses accordingly. Heavy sweating due to the summer heat can also affect how well continuous glucose monitors (CGMs) stay on and work as intended, meaning glucose levels can change without people noticing, potentially leading to hyperglycemic emergencies.

Warning Signs Diabetic Patients Should Never Ignore in Hot Weather

Triple-digit temperatures can cause heat exhaustion, causing individuals’ bodies to overheat and sweat profusely. People living with diabetes may not be able to regulate their internal temperatures properly. For people with this condition, heat exhaustion can quickly transform into heatstroke, which is a life-threatening condition.

Knowing the signs of heat exhaustion in diabetic patients can help reduce the risk of developing complications and ED visits. The following are some of the most common signs of heat exhaustion according to the Mayo Clinic:

• The person is heavily sweating, but the skin is clammy, cool, and moist with goose bumps
• The pulse is rapid but weak
• Dizziness
• Fatigue
• Muscle cramps
• Low blood pressure upon standing (which can cause lightheadedness, dizziness, or feeling faint)
• Nausea
• Headache

To address heat exhaustion, individuals should:

• Stay in a cool, shaded place. Ideally, in an indoor space with air conditioning.
• Drink plenty of water.
• Change into loose-fitting clothing.
• Use a cooling towel, spray, or cold packs to help your skin cool down.

Learning the signs of heat exhaustion and addressing them as quickly as possible can help people living with diabetes prevent more serious complications and reduce the chances of requiring emergency care. As much as possible, stay indoors when temperatures are surging, keep hydrated, and monitor your blood glucose levels regularly to stay safe and healthy amid the devastating summer heat.