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For people with type 1 diabetes (T1D), it’s not all fun and games when it comes to hanging out in swimming pools, sunning at the beach, or relaxing in a hot tub.

The ideal resort vacation, or just a dip in a friend’s Jacuzzi, can turn ugly fast if you aren’t well-prepared with regard to insulin and the medical devices many of us wear stuck to our skin.

Whether you’re managing your T1D old-school with syringes or using the hottest new diabetes technology, there are a few critical details you need to know.

Before you even dip your toes in the water, you need to start thinking about where your diabetes “gear” is and how hot it is in that location. An insulin pump full of overheated insulin is a fast way to land in the ER hours later in diabetic ketoacidosis (DKA).

The hottest temperature insulin can withstand before it starts to break down (which means it will not affect blood sugar properly) is 86 degrees Fahrenheit. The ideal temperature for insulin longevity and efficacy is between 36 to 46 degrees. Note that some glucometers will also stop working if they overheat.

Even if your insulin is tucked in your bag, it’s absolutely critical that you do not leave it in the direct sun or leave it in your very hot car. Always keep your diabetes stuff out of the direct sun as well, which mean putting it under an umbrella or a towel if there’s no other shade to be had.

You can protect your insulin pens and vials with one of the following approaches:

  • Simply place an ice pack in your bag that sits next to your diabetes kit. This of course will melt, but will give you and hour or two of protection depending on how hot it is outside. Remember not to put your insulin directly on top of an ice pack. Freezing insulin is just as destructive as overheating it.
  • Purchase a Medicool pack or poncho that are designed to keep the ice packs in the right place.
  • Or better yet, purchase a FRIO pack, which is activated by water and keeps insulin temperature controlled for up to several days.

What about the insulin inside the pump or pod you may be wearing on your body in the sunshine?

Yes, insulin can overheat in your pump or pod when it’s on you, explains Aimee Jose, RN and diabetes educator at Steady Health in San Francisco.

“Keep your body facing the shade if possible. But in the hot sun for an hour or so will likely not do much. It’s the direct sun that does the most damage. If it’s covered by your shirt, you have that extra layer of protection,” says Jose.

Even if you aren’t at the beach or the pool, it’s important to remember that insulin and sunshine do not get along well.

“All pumps have IPX ratings and are water-resistant,” Jose tells DiabetesMine.

An IPX rating tells you just how much water any product can tolerate, from a couple drips to a splash to a full 20-minute dunk in the pool.

“In general, today’s pumps are approved for depths up to 25 feet for 60 minutes but you should review your pump’s manual to get the specifics for each pump and other diabetes technology,” Jose explains.

While all of today’s newest continuous glucose monitor (CGM) sensors and transmitters are waterproof, the receiver (the part where you read your actual blood sugar level) is not. Keep in mind that your sensor and transmitter may lose communication with your receiver if you swim too far from it. Older CGM transmitter models may lose communication ability with the receiver when submerged in water as well.

The newest pump-CGM system from Medtronic, the Minimed 670G, can handle up to 12 feet of water for 24 hours. The sensor and transmitter are water-resistant, but the receiver is not.

Depths beyond 25 feet raise the question of scuba diving, which is only recommended for people with very tightly managed blood sugars and no diagnoses of retinopathy, neuropathy, vascular issues, or cardiac issues.

Speaking of the ocean, Jose adds that it’s important to wash or wipe off the salt water after immersing your pump in the ocean. And of course, absolutely aim to prevent sand from getting on or into your pump or other technology.

In case of an accident or unexpected dysfunction in your diabetes technology, she recommends carrying a back-up fingerstick glucose meter and test strips. For longer trips to the beach, it’s extremely important to bring back-up insulin and syringes or pen needles with you in case your pump is damaged by water, sun, and sand.

For many, the preferred choice is to disconnect from your insulin pump when swimming for increased comfort and mobility. While it seems simple, there are a few things you must take into account before, during, and after disconnecting.

Jose offers the following steps for disconnecting from your pump before swimming:

  1. Make sure you store your pump in a shaded, cool location. Do not leave it exposed to direct sunlight.
  2. If you are disconnecting for longer than 30 minutes, you should give yourself a bolus dose for the amount of basal insulin you’re going to miss. For example, if your basal rate at that time of day is .5 units per hour, and you’re disconnecting for 1 hour of swimming, you would give a bolus of .5 units prior to swimming. Make sure to let the entire dose administer, and then disconnect. If your swim-time is cut short for any reason, remember not to reconnect any sooner than 1 hour otherwise you could risk getting extra basal insulin.
  3. Use additional adhesive if necessary to protect your infusion site and CGM sensor site from coming off due to prolonged time in the water. Popular sources include Rock Tape, GrifGrips, Skin Tac, or Simpatch.
  4. Consider using a waterproof case for your pump if you do plan to keep it on while swimming for an extended period of time from sources like AquaPack and Medtronic.
  5. Don’t forget that swimming is exercise! Depending on the intensity of the swimming you’re doing, you may need to plan ahead to prevent low blood sugars by reducing your basal rate for during the hour before you swim based on your healthcare provider’s recommendations. For some, this could be a 70 percent reduction, for others perhaps only 25 percent. It depends greatly on the type and intensity of your water activity.
  6. If you eat a meal prior to swimming, you’ll want to reduce your bolus for that meal by approximately 50 percent or per your doctor’s recommendations to prevent hypoglycemia during the hour or two following that meal.

If you don’t use a pump, you may need to consume an extra 10 or 15 grams of carbohydrate for every hour of intense water activity to prevent low blood sugars just like you would for other types of aerobic exercise.

Hot tubs are supposed to be a source of relaxation, but for a person with T1D, it requires careful precautions, too. (In fact, diabetes guru Dr. Bernstein objects to them entirely.)

For most people, the first concern is low blood sugar.

“Sitting in a hot tub or even standing in a hot shower can significantly increase your blood flow,” explains Jose. “This can lead to an unexpected low blood sugar because the increased blood flow is moving insulin faster through your entire bloodstream.”

For multiple daily injections: Do not take a full bolus of insulin for a meal or to correct a high blood sugar before getting in a hot tub. Doses should be reduced by at least 50 percent or otherwise as recommended by your healthcare team.

“The effect of very hot water on your blood sugar is very individualized. Be smart,” adds Jose.

For insulin pumps: The heat of the water in a hot tub will destroy your insulin if submerged in that water for more than a few minutes. Most hot tubs are well over 95 degrees, which means regardless of whether it’s water-resistant or not, an insulin pump should never be submerged.

You should always disconnect from your pump before getting into a hot tub,” Jose says. “If you use an Omnipod, it must be on your upper body where you can keep it above the water level.”

If you do accidentally immerse your pod in the hot water for too long, you should keep a very close eye on your blood sugars during the few hours afterwards. Signs of increasing high blood sugars could indicate that the insulin that pod is no longer effective and you’ll need to put on a new pod immediately to prevent DKA.

It’s important to remember that even after disconnecting from your pump, there is still insulin sitting in the cannula from your administered basal rate. Depending on the length of your cannula, it could be .3 to .7 units of insulin.

“The insulin in the cannula will heat up and lose its potency during time in a hot tub,” says Jose. “This is part of your basal rate, so you could end up with a high blood sugar when you combine this damaged insulin with the time spent off your insulin pump.”

The ideal way to use a hot tub if you use an insulin pump is between site changes, recommends Jose. While that’s easier said than done, she explains that timing your infusion site change around your hot tub soak is the best way to prevent damaging your insulin.

Always monitor your blood sugar very closely after using a hot tub to be sure you’re getting good insulin. If you’re experiencing stubborn highs, your insulin may have been damaged and you’ll need to set-up a new pod.

If you have neuropathy: “The more severe the neuropathy, the greater concern when using a hot tub,” explains Dr. Calvin Wu, an endocrinologist at Steady Health.

“The main concern is that a person with T1D might burn themselves and not feel it,” Wu explains.

If you have neuropathy in your feet and legs, it’s critical to limit your hot tub use to a short session, and monitor the condition of your feet and legs while immersed in the water. With some hot tubs as warm as 104 degrees, it can be easy to overdo it. If your feet and legs are becoming noticeably red, you should exit the hot tub immediately and let your body cool down.

If you have open wounds or infections: If you’ve struggled to maintain the recommended A1C level at or below 7.0 percent, and also struggle with infections or wounds and blisters that aren’t healing well, a hot tub session could further worsen that infection or wound.

Before entering a hot tub, be sure to examine your feet and toes carefully, as well as your fingers to ensure you’re not on the brink of infection or unnoticed open wound. Your doctor may recommend avoiding hot tub use altogether.

Being prepared for low blood sugar while swimming or relaxing in a hot tub is as crucial as being prepared during any other type of exercise. Here are a few things to keep in mind when deciding what types of fast-acting carbohydrates to carry with you:

  • Something that will not melt or rot in the heat (a juice box, chocolate, or fresh fruit is not a good idea).
  • Something that can treat multiple low blood sugars (one piece of fruit can only treat one low).
  • Something that can be stored in a waterproof container if, for example, you’re taking it with you in a kayak or canoe.
  • Ideal sources include glucose tabs or gel, gummy candies, jelly beans, Pixie Stix, etc.

Also remember to inform everyone you’re swimming with about your diabetes. If you’re frolicking in ocean waves and distracted by the fun, it could be easy to overlook symptoms of hypoglycemia. Let your friends be part of your team and ask for help if you need it.

Can you have fun in the water as a person with type 1 diabetes? You bet. But like many other aspects of our lives, we have to acknowledge and respect the challenges, demands, and responsibilities that are necessary in order to swim safely. It’s important to think ahead about storing all your gear properly, bring backups, and make sure your companions are in the know in case of emergency.


Ginger Vieira is a type 1 diabetes advocate and writer, also living with celiac disease and fibromyalgia. She is the author of “Pregnancy with Type 1 Diabetes,” “Dealing with Diabetes Burnout,” and several other diabetes books found on Amazon. She also holds certifications in coaching, personal training, and yoga.