Hot water bottle burns and how to treat them

Published: September 2025

Your skin is delicate and can be damaged from exposure to heat sources for extended periods of time such as from having a laptop resting on the legs for too long, or from holding a hot water bottle on the body.

This article will delve into the dangers of using a hot water bottle for too long and how to treat complications if they occur.

Hot water bottle burns, also known as toasted skin syndrome and medically as erythema ab igne, is a type of skin condition that can cause complications such as burning sensations, itching, redness and skin discolouration.

As mentioned above, this occurs when your skin is exposed to a heat source for extended periods of time. Although it’s classified here as a ‘burn’, the heat source is not hot enough to actually burn through your skin. For example, a curling iron burn is different as it directly burns through the skin, potentially causing infection and scarring.

Low grade heat, from temperatures of 43 to 47 degrees Celsius, will typically cause a prominent circular area of discolouration accompanied by redness in the area that is affected.

There are several potential sources of heat that cause burns, and isn’t exclusive to hot water bottles, although more common in the modern day. Hot water bottle burns can cause burns on the skin if the water inside is too hot, or if the bottle is applied directly onto bare skin for extended periods of time. In years gone by, burns were often caused by other practices that are not as common today, such as those who worked with hot coals and wood burning stoves. Staying near these sources of heat for extended periods of time can cause irritation and burning of the skin.

Other causes of toasted skin syndrome include:

• Seated heats in cars: This can cause toasted skin burns on the buttocks and back of the legs if used for long periods of times.
• Metalworking: Working around hot furnaces can also cause the skin to burn. Not as common, as improved safety procedures and better PPE reduceds the likelihood of this occurring.
• Bakers: Exposure to high temperatures from hot ovens can cause toasted skin syndrome. Not as common in the modern day due to improved oven safety and procedures in modern bakeries.
• Space heaters: Older people would have been more likely to be impacted by burns caused by space heaters or radiators, as they would have spent a lot of time directly in front of them for warmth during the winter months.

Generally the tell-tale sign of a hot water bottle burn is a rash that appears in a fishnet pattern.

Firstly, you may notice the rash as pink and blotchy. When pressed, it may turn pale or white momentarily.

Over a longer period, the rash will become brown, purple or red. Touching or pressing the rash at this stage will not stay pale or white but instead will keep the same colour.

The rash will emulate a lace-like pattern, and you may notice the skin as thinner or thicker than usual, with a chance of developing blisters.

The rash itself is not an issue or particularly bothersome, however, it can be itchy, painful or have a burning sensation in some people.

As mentioned above, blisters can form as a symptom of erythema ab igne caused from a hot water bottle, and this can happen depending on the severity of the burn itself.

Erythema ab igne does not tend to be permanent, especially if the heat source is moved away from the skin as soon as possible. Upon removal, the condition should resolve soon after.

However, erythema ab igne from hot water bottle burn can become permanent if not treated promptly once symptoms become more severe.

In the event of a hot water bottle burn, you should immediately address the issue and attempt to cool the area, whilst keeping the rest of the body warm. Here are some steps to follow if you are affected by a hot water bottle burn:

The first immediate step should be to remove the heat source, in this case a hot water bottle, away from the area to ensure no further damage is caused. The quicker this is done, the more likely it is that the discolouration and redness will fade.

You should aim to cool the area for about 20 minutes, by placing the burn under cool, running water and keeping the rest of the body warm. This will help ensure the burn does not get worse and provides immediate relief.

Once you have removed the heat source and cooled the area, you may find using certain topical creams can help to soothe any itching, irritation and general discomfort from toasted skin syndrome.

Ointments like the Elastoplast Wound Healing Ointment can support the healing of wounds, damaged skin and burns. It helps reduce the risk of scarring and can be used in all stages of wound healing.

A dermatologist can also help determine whether you perhaps need a topical medication like retinoids, as these can also help with symptoms from hot water bottle burn and toasted skin syndrome.

Preventing hot water bottle burn and other potential causes of toasted skin syndrome entails being cautious and aware of the heat sources you are using at all times. Tips to prevent include:

• Avoid spending too much time with a heat source near or on your skin
• Never apply the heat source directly onto the skin for extended periods
• Always follow safety procedures for each source (especially for work reasons)
• Never overfill hot water bottles (no more than two thirds) and ensure the water is warm not boiling
• Avoid sitting or lying down on the hot water bottle

Heat sources like hot water bottles, stoves, ovens, heating pads, laptops and open fires can all be a cause of toasted skin syndrome.

Depending on the severity, there can be complications that occur as a result of erythema ab igne or toasted skin syndrome.

As mentioned above, it’s possible for the condition to resolve immediately after the removal of the heat source, however, if this is not done and there is a signficant delay in diagnosis along with persistent exposure, it can lead to more serious conditions. It can lead to permanent pigmentation or progression to Merkel cell carcinoma, basal cell carcinoma and squamous cell carcinoma1.

1. Erythema Ab Igne: A Rare Presentation of Toasted Skin Syndrome with the Use of a Space Heater, Cureus. 2021 Feb 17;13(2):e13401