Diabetes in the Heat Overlooked Risks That Could Cost Lives
Why extreme heat poses unique dangers for people with diabetes and how both patients and providers can adapt safely
Extreme heat impairs the body’s ability to regulate temperature in people with diabetes, increases hospital admissions, and can interfere with insulin absorption and glucose monitoring. Tailored treatment adjustments and preventive measures are essential during heat waves.
Study Details
Experts from the German Diabetes Center (DDZ) and the University Hospital Düsseldorf highlight that diabetes alters the body’s natural cooling mechanisms, raising the risk of overheating, dehydration, and heatstroke. Hospitalizations for people with diabetes increase by up to 25% during heat waves, especially among older adults, those with high HbA1c levels, and those on insulin therapy.
Methodology
This analysis draws on epidemiological data linking hospital admissions to heat waves, clinical knowledge of impaired thermoregulation in diabetes, and pharmacological studies on how heat affects insulin absorption, blood glucose monitoring, and drug metabolism. Clinical guidance from the German Association of General Practitioners’ Heat Manual is included for safe practice recommendations.
Key Findings
Impaired heat regulation: Neuropathy and kidney disease reduce sweating and blood flow to the skin, making cooling less effective.
Higher comorbidity burden: Cardiovascular disease, hypertension, and obesity compound the risk.
Therapy complications: Heat accelerates insulin absorption, risking hypoglycemia, while dehydration impairs insulin signaling, raising glucose levels. Other common medications, including diuretics and beta-blockers, further reduce heat tolerance.
Device vulnerabilities: Insulin pumps and rt-CGM systems can malfunction in high temperatures, with risks of denatured insulin, clogged tubing, or sensor inaccuracy.
Implications for Practice
For people living with diabetes, the risks posed by extreme heat go well beyond discomfort. Staying hydrated becomes critical, even in the absence of thirst, since dehydration directly alters blood glucose control. Insulin and other medications should always be kept cool, ideally between 36 and 46 °F, and never left in direct sunlight. Special cooling pouches can be used to protect insulin pens and pumps, and blood glucose meters or test strips should also be shielded from high temperatures. Physical activity is best shifted to early morning or late evening hours to avoid dangerous peaks of heat exposure, while swimming should be approached with caution because adrenaline can mask symptoms of hypoglycemia. More frequent glucose checks are essential since metabolism may shift unpredictably during heat waves.
For clinicians, awareness of these challenges is vital during the hotter months. Hospitalizations are known to rise during heat waves, and patients with higher HbA1c values, multiple comorbidities, or insulin therapy are particularly vulnerable. Medication plans may need to be reassessed, especially because heat can accelerate insulin absorption while dehydration undermines its effectiveness.
Common prescriptions such as diuretics, beta-blockers, or certain antidepressants can further lower heat tolerance and increase cardiovascular risk. Providers should actively counsel patients on hydration strategies, safe storage of medications and devices, and signs of heat stress, while also considering potential adjustments in therapy to maintain stable glucose control during periods of extreme heat.