Looking after yourself and diabetes in hot weather

Summer has officially arrived! You may be looking forward to enjoying some fun in the sun, however it is important to be mindful that the warmer weather can also have an impact on your diabetes and will require some extra considerations.

Some of the most important things to be aware of when you have diabetes include your increased risk of dehydration, heat exhaustion and heat stroke.

During hot weather we sweat more to help our bodies cool down. Sweating more means that our body is losing more fluid than usual. Less fluid means blood glucose is more concentrated, resulting in a rise in glucose levels.

People with diabetes have an increased risk of dehydration.

Your body tries to get rid of the extra glucose, by passing it out through the kidneys in your urine – also taking water with it. This results in your body losing extra fluid which can increase your level of dehydration.

To help avoid dehydration it is important to make sure you’re drinking enough water to keep up with this loss. Tips include:

Drink water – even if you don’t feel thirsty.
Avoid alcoholic, hot, or sugary drinks (including tea and coffee) as they can make dehydration worse.
If you go outside, carry a water bottle with you.

The colour of your urine can help you to know if you are drinking enough water to prevent dehydration. Use this urine colour chart to check how hydrated you are healthdirect.gov.au/urine-colour-chart

People with diabetes have an increased risk of heat related illness.

Heat related illnesses – including heat exhaustion and heat stroke can affect anyone, however some groups including people living with existing medical conditions such as diabetes are at an increased risk.

Why are people with diabetes at risk?

Damage to blood vessels and nerves as a complication of diabetes may make it more difficult for your body to be able to regulate its temperature and cool down during warm weather.

Heat exhaustion

Heat exhaustion is your body’s response to a loss of water and salt in hot weather, usually through excessive sweating or excessive physical activity.

Symptoms can include:

pale skin
headaches
dizziness
weakness
nausea and vomiting
tiredness
muscle cramps
feeling thirsty and
heavy sweating.

If you experience the symptoms of heat exhaustion, act at once. Move to a cool place to rest and drink water. Start to cool down any way you can such as using a cold-water spray, applying a cool, damp sponge or cloth, or having a cool bath or shower.  

Heat stroke

Left untreated, heat exhaustion can lead to the more severe and potentially life-threatening condition known as heat stroke.

Symptoms of heat stroke include:

confusion
hallucinations
rapid breathing and convulsions.

Heatstroke is a medical emergency. If someone is experiencing symptoms of heat stroke call triple zero (000) straight away and ask for an ambulance.

Also remember that symptoms of hypoglycaemia and heat exhaustion can be easily confused – so if in doubt check your glucose level and act accordingly.

Find out more information about heat exhaustion and heat stress here.

Hot weather can affect insulin absorption.

If you use insulin to manage your diabetes, hot weather can change the way that it is absorbed by your body. Heat causes your blood vessels to dilate (open up) which may mean that your insulin will be absorbed more quickly from the injection site. This in turn can increase your risk of having a hypo (low blood glucose level).

Be aware of this and make sure to check your glucose level more often on hot days and always carry hypo treatment with you.

To find out more about hypoglycaemia click here.

Continuous Glucose Monitor (CGM) readings

Continuous glucose monitoring (CGM) devices read the amount of glucose that is in your interstitial fluid. This is the fluid that surrounds the cells in your body.

Dehydration can affect the circulation of your interstitial fluid, which means that your sensor glucose reading may not be accurate. If you are unsure if you might be dehydrated, or your symptoms do not match how you feel, always do a finger prick check to confirm your glucose level.

Sunburn

There are two things to consider with sunburn.

1. Sunburn can increase glucose levels.

Sunburn causes pain, stress on the body and may result in dehydration. It is common to see an increase in blood glucose levels if you are sunburnt. During this time your medication or insulin dose may need to be adjusted to help keep your glucose levels in target.

2. Increased risk of sunburn with some diabetes medications

Some medications used to manage glucose levels can also increase your sensitivity to sunlight, meaning that you may burn more easily or have skin irritations such as a rash, itchiness, and redness.

These medications come from the sulphonylurea family and include the active ingredients gliclazide, glimepiride, glibenclamide and glipizide.

If you are not sure if your medication is one of these, check with your doctor, diabetes educator or pharmacist.

To reduce your risk of sunburn, remember to stay inside or in the shade on days where the UV index is rated as high. If this cannot be avoided, wear sunscreen, hat, sunglasses, long sleeved tops and pants when possible.

More information about staying SunSmart can be found here.

Storage of medication, insulin and diabetes devices

Keeping your diabetes medications, insulin and diabetes devices away from heat and direct sunlight is critical to ensure that they are not damaged and can work as intended.

Diabetes devices include things such as blood glucose meters, glucose test strips, glucose sensors and insulin pumps.

Most diabetes devices and medications should be kept at room temperature. In warmer weather this may become more difficult. Look for a place that stays cool and is not in direct sunlight.

Some injectable diabetes medications and unopened insulin should be stored in the fridge.

If you are unsure about the storage of any of your diabetes medications or devices, contact the device company, your diabetes health care team or pharmacist for advice. 

When you are out and about, your diabetes medications and supplies should be stored in a suitable cool bag or storage container. A range of suitable products can be found here.

Footcare

Taking care of your feet is essential during the summer months, especially if you have impaired sensation to your feet (known as peripheral neuropathy). During the warmer weather our feet are often exposed more to our environment, meaning that they are also exposed to a greater risk of injury.

Remember:

Don’t go barefoot.
Wear sandals or shoes when walking on hot surfaces such as sand at the beach.
Apply sunscreen to any exposed skin on your feet to protect them from sunburn.

Physical activity

Exercise is an important component of managing your diabetes. Some tips to do this safely in the warmer weather include:

Exercise either in the early morning or late evening which is likely to be the coolest part of the day.
Exercise in air-conditioned environments or a swimming pool.
Remember to stay well hydrated.
Check your glucose level before, during and after exercise.
Carry hypo treatment with you.

Plan for emergencies

The risk of emergencies such as power outages, bushfires and natural disasters is higher in the summer months.

Planning for an emergency before it happens can help with your diabetes management at a stressful time.

The National Diabetes Service Scheme (NDSS) has a free resource to help you plan for natural disasters and emergencies. 

Is sunshine good for you? 

Despite the extra considerations needed for managing your diabetes care during the warmer weather, there is no reason for diabetes to hold you back from having fun!

The warmer weather provides many benefits to your mental health and overall general health. Sunshine can boost your mood and reduce stress. It can also encourage you to be more active.

The sun is also a source of Vitamin D, which plays several important roles in the body. These roles include keeping your bones, teeth, joints and muscles healthy, and supporting immune system function. Recent research has revealed that vitamin D can be an important part of blood glucose management. 

In summary, hot weather can affect your glucose levels and diabetes management. Being mindful of these impacts and planning around them can help you to feel well prepared and get the most out of the warm weather.

Have fun in the sun!

 For more information on these topics: 

Article published January 2024.

Renae Roll

registered nurse (RN) and credentialled diabetes educator (CDE) at Diabetes Victoria

I have worked at Diabetes Victoria for 16 years as a Diabetes Nurse Educator. Prior to my role as a Diabetes Nurse Educator, I was an emergency nurse at St Vincent’s Hospital in Melbourne.

I am a parent to two children aged 12 and 15 years. In my spare time I like to exercise, cook, read and catch up with friends.