Some people who’ve had cancer continually feel too hot or too cold when those around them find the temperature fine. Problems with temperature regulation have been reported by people after having breast, lung, prostate and testicular cancers. Having a high temperature can also be a danger sign. Here we look at the reasons for problems with temperature regulation and also tell you what to watch out for.

Why you might have problems with temperature

There are a number of reasons why temperature regulation is affected by cancer and treatment.

  • Some cancers, such as lymphomas cause fever symptoms. This is often an early diagnostic sign.
  • Some hormonal treatments cause hot flushes, for example for breast or prostate cancer.
  • Treatment lowers your risk of infection so a high temperature is a sign that you need to contact your doctor or hospital.
  • Weight loss due to cancer can make it harder for you to keep warm as you have less body fat.

But we’re now realising that some people who have (or have had) cancer seem to have general problems with feeling too hot or cold for no particular reason. We don’t yet know exactly why this is, but there are a number of theories. 

Theories on what’s going on

One of the main theories centres on cytokines. These are a group of proteins that cells use to signal to each other. They can be over produced by some cancers and their levels can also be affected by treatment. They’re involved in cell growth, immunity and temperature regulation. 

Raised cytokine levels are linked to a number of persistent problems reported by people with cancer, including fatigue, sleep disturbance, depressed mood, and loss of appetite. These problems can persist for a long time after diagnosis, so it’s possible that altered cytokine levels are responsible for long term temperature disturbance too. 

Your body uses up a lot of energy in running your immune system and in keeping warm. There’s even a theory that feeling cold is your body’s way of telling you that you need to conserve heat or give your body more energy (ie food!) to boost your immune system.

Thyroid hormones are involved in normal body temperature regulation. People with thyroid problems often have problems with feeling too hot or cold. Levels may be affected by cancer treatments. Anaemic (low iron levels and red blood cell count) can also make you prone to feeling cold.

There may be factors at work that are little to do with the cancer directly. We know that older people are not as good at regulating their temperature when it’s cold, probably because their bodies aren’t as good at narrowing small blood vessels to conserve heat. If you’ve lost weight, you have less body fat, which helps to insulate you against the cold. 

When feeling too hot or cold is a problem

If you have a raised temperature because of an infection you may feel hot, but initially you may feel very cold. If you have chills and shivering or feel at all unwell, take your temperature. If it’s 38 C or above, contact your doctor (it's worth noting that different cancer centres define a fever with different temperatures, so it's best to check with them). This is particularly important if you are having treatment and your natural resistance to infection is lowered. Taking paracetamol or ibuprofen will help to lower your temperature, which will help you feel more comfortable until any treatment your doctor prescribes for infection kicks in. Drink plenty as you are more prone to becoming dehydrated when you have a temperature.

What you can do about feeling hot or cold

Hot and cold…

  • Ask your doctor whether you need to have your thyroid hormone levels checked
  • Wear layers so you can remove or add clothes more easily to suit how you are feeling
  • Have layers of bed clothes instead of a duvet so you can more easily add or remove during the night

Feeling too hot…

  • Run cold water over your hands and wrists
  • Spray your face with cold water or a cooling spritz
  • There are cooling gel packs, pillow mats, scarves and wrist bands available to buy
  • Have regular cold drinks and cold meals if eating makes you hot
  • Start with tepid water when bathing or showering and increase the heat gradually
  • Use a desk or hand held fan
  • Caffeine may not help, so avoid tea and coffee or have decaff

Feeling too cold…

  • Ask your doctor if you could be anaemic – a blood test will check your haemoglobin level
  • Make sure you eat enough – your body needs the energy to produce heat
  • Hot drinks will help you to feel warmer
  • Avoid alcohol - it tends to cause your body to give off heat
  • Use heat pads or hot water bottles to keep you warm at night without overheating your partner
  • Don't sit still for too long - exercise generates body heat and will help you to feel warmer