Hot water in showers and baths can affect blood sugar levels. Some report blood sugar spikes during and afterward, while others may experience lower levels and hypoglycemia.

Taking a hot shower or bath can affect your blood sugar, with some people with diabetes experiencing higher levels and others seeing drops to the point of having low blood sugar in the hours afterward.

There is no clear reason why people have differing experiences with hot or steamy water, whether it’s a few-minute-long shower or bath, or a longer soak in a steamy, relaxing environment.

Many people with diabetes, especially those who wear continuous glucose monitors (CGM), share that they experience higher blood sugar levels after being in a hot shower, bath, or hot tub.

Both research and anecdotal reports — especially from people with type 1 diabetes who may wear diabetes devices that help more closely monitor blood sugar levels — suggest a temporary rise in blood sugar during or immediately after a hot bath or shower. This is sometimes referred to as a “false high.”

This may be a result of stress hormones being released in response to the heat, including adrenaline and cortisol. This response in your body can counteract insulin and cause the liver to release stored glucose, leading to higher blood sugars.

For those wearing CGM sensors, some research also suggests that the interstitial fluid under the skin that the sensor uses to monitor glucose levels may flow more loosely because of the heat, and that can cause blood sugar spikes.

This 2023 study found that for some healthy males, hot water immersion might reduce the amount of glucose absorbed into the body, leading to a temporary rise in blood sugar levels.

What about heat immersion therapy?

Some research on repeated hot water immersion (heat therapy) has shown potential long-term benefits, including for people with type 2 diabetes and possibly insulin resistance.

Activation of certain proteins (like heat shock proteins) may help improve insulin sensitivity in the body and reduce inflammation, leading to lower blood sugars. When combined with exercise, this may also help with fasting plasma glucose and A1C levels. However, research isn’t large enough or conclusive on this possible benefit.

Some people also share anecdotes of watching their blood sugar drop lower after they’ve taken a bath or shower.

Research suggests this is a result of extreme heat and hot water on your skin, as it can cause blood vessels to widen and more quickly absorb insulin in your body. If you’ve recently taken any insulin and have insulin on board (IOB), this faster absorption could lead to blood sugar drops and hypoglycemia.

This research suggests that for people with type 2 diabetes, steam baths could be another way to help lower blood sugar levels.

But more research is needed to explore that issue, beyond small clinical studies and anecdotal reports of the possible benefits of showers and baths using hot water.

Consult your diabetes and healthcare teams for guidane on how heat and hot water may affect your blood sugar levels, and how that may play a part in your diabetes management.

Yes, you can use a hot tub if you live with diabetes. You may just consider taking additional steps and precautions, especially if you wear a diabetes device like an insulin pump or CGM to monitor glucose levels.

For the same reason that steamy showers and baths can affect blood sugar levels and increase the risk of hypoglycemia, hot tubs can also have this effect. The increased blood flow in hot tubs moves insulin faster throughout the body.

Some suggest that people using insulin avoid taking a full mealtime or correction bolus before getting into a hot environment, and instead take a lower amount to help accommodate any blood sugar swing. Your healthcare team is best to guide you on any insulin dosing or diabetes management changes needed.

Can you wear diabetes devices in hot tubs?

The heat from the hot tub water can also be dangerous for the insulin inside the pump and the infusion site’s cannula, which delivers insulin under your skin. Most hot tubs are hotter than 95 degrees, which means an insulin pump should never be submerged, regardless of whether it’s water-resistant or not.

  • Traditional tubed pumps should be disconnected before entering a hot tub.
  • Omnipod patch pumps can stay attached as long as they are on the upper body and above the heated water.
  • CGM sensors have similar guidance about not submerging and keeping them above hot water, if possible.

Aside from diabetes, there may be other health benefits of hot tub use that are worth considering beyond blood sugar management. This may include muscle relaxation, pain relief, and better sleep.

How do diabetes complications affect showers and baths?

People who experience certain diabetes-related complications may also need to take special precautions when using showers, baths, and hot tubs.

This is especially true for those with diabetes-related neuropathy, a common diabetes complication where nerve damage can affect the feet, toes, hands, and other parts of the body. Numbness or less feeling in parts of the body could mean not being able to properly detect how hot water is in a shower or tub, possibly leading to burns from hot water.

Keep these things in mind when taking a shower or bath in hot water, if you live with diabetes and use insulin.

  • Risk of hypoglycemia: Because insulin absorption is potentially faster, be mindful of your shower or bath timing relative to your insulin doses, exercise, and food intake.
  • Possible false high blood sugars: Remember that heat and hot water may affect your glucose readings, especially with CGM technology. While you may initially observe a higher reading, give it some time before taking any insulin to correct that level in case your blood sugars stabilize once your body temperature levels gradually decrease.
  • Neuropathy effects: If you have this diabetes complication in your hands, feet or toes, you might not be able to accurately sense the water temperature. This can increase your risk of severe burns that can be slow to heal. Always check the water temperature properly before getting into the shower or bath, using your elbow, a non-neuropathy part of your body, or a thermometer.
  • Device management: Ensure that diabetes technology is not exposed to water and store it in a dry, secure location away from potential water damage. Also, be cautious with countertops or other smaller surfaces, especially if your device vibrates with alerts when you’re not connected, and may fall off the counter onto a hard floor.

If you are considering regular heat therapy (like a hot tub) to help manage your blood sugar, discuss it with a healthcare professional first, as they can provide guidance specific to your condition and medication.

Hot water in showers and baths can affect blood sugar levels. Some report blood sugar spikes during and afterward, while others may experience lower levels and hypoglycemia. Those taking insulin may experience blood sugar drops as a result of the heat, causing insulin to work faster and lowering glucose levels.