Managing Diabetes in the Heat

People with type 1 or type 2 diabetes feel the heat more than people without it.

Why heat hits harder

• Cooling: diabetes complications such as damaged blood vessels and nerves can affect sweat glands, so the body can't cool as well — risking heat exhaustion and heat stroke, a medical emergency.
• Dehydration: people with diabetes dehydrate faster. Too little fluid raises blood sugar, and high blood sugar makes you urinate more, dehydrating you further. Diuretics ("water pills" for high blood pressure) add to it.
• Insulin: heat changes how your body uses insulin, so you may need to test more often and adjust insulin, food and drink.

Heat plus humidity

Sweat cools you by evaporating, which it can't do well in humid air — so even a day that doesn't feel very hot can be dangerous.

• Check the heat index, which combines temperature and humidity. Take steps to stay cool once it reaches 80°F in the shade with 40% humidity or more.
• Stay in the shade: in full sun the heat index can be up to 15°F higher.
• Exercise smart: physical activity is key to managing diabetes, but avoid outdoor activity in the hottest part of the day. Go early or in the evening, or work out somewhere air-conditioned — at home, a mall or a gym.

Keep an eye on blood sugar

Summer — kids home, vacations, reunions — can upset your routine and your diabetes plan. Check your blood sugar more often to stay in range, and learn to recognize and quickly treat low blood sugar.

Warm-weather tips:

• Drink water even if you're not thirsty.
• Skip alcohol and caffeinated drinks — coffee, soda, energy and sports drinks — which cause water loss and can spike blood sugar.
• Test before, during and after activity; you may need to change your insulin.
• Wear loose, lightweight, light-colored clothes.
• Use sunscreen and a hat — sunburn can raise blood sugar.
• Don't go barefoot, even at the beach or pool.
• Stay somewhere air-conditioned; in very high heat, a fan isn't enough.

Protect medicines and gear

Heat harms diabetes medicines, supplies and equipment too.

• Medicines: don't leave insulin or pills in direct sun or a hot car; check the package for heat warnings. When traveling, keep insulin in a cooler — but not directly on ice or a gel pack.
• Equipment: heat can damage your meter, insulin pump and test strips. Keep them out of hot cars, away from pools and beaches, and out of the sun.
• Still bring them: you need to be able to test and treat highs and lows when you're out — just keep your gear protected.

Storm season

Hurricane season starts June 1, and severe thunderstorms, hail, high winds and tornadoes are more likely in warm weather. A power outage or evacuation is harder with diabetes: plan how you'll keep insulin and other refrigerated medicine cool, and be prepared with an emergency go-bag.

Summer checklist

• Drink plenty of water.
• Test your blood sugar often.
• Keep medicines, supplies and equipment out of the heat.
• Stay in air-conditioning at the hottest times.
• Wear loose, light clothing.
• Get medical help for heat-related illness.
• Plan for a power outage.
• Keep a go-bag ready.

Sources

Based on "Managing Diabetes in the Heat," Centers for Disease Control and Prevention; a work of the United States government in the public domain.