This leaflet answers common questions about having a thermal threshold study. If you would like further information, or have any worries, please do not hesitate to ask the physiologist performing your test.

A physiologist will explain the study to you on the day of your appointment and answer any questions you may have.

What is a thermal threshold study?

Thermal thresholds are a test of the small nerve fibres in the hands and feet that allow you to feel if something is hot or cold. This test helps us understand if the small nerve fibres are sending the correct temperature signals to your brain.

What will happen during the test?

A small object will be placed on the skin of the hand or foot. We can control the temperature of the object, and it will slowly become warmer or colder. We would like you to tell us as soon as you notice any temperature difference. We may repeat this process several times to get an accurate result. The test can take up to thirty minutes.

The test will take place in the neurophysiology department at Royal Free Hospital on the first floor, behind clinic 2.

Before the test

To prepare for the test, please:

  • Remove all moisturiser, lotion, or oil from the skin.
  • Wear short-sleeved clothes and loose trousers so you can easily expose the arms and legs.
  • Remove watches and wrist jewellery (a wedding ring may be worn).

After the test

The results of your test will be sent to the clinician who requested the test. We will not be able to provide a report on the day of the test as the study needs to be analysed.

Risks and side-effects

Thermal threshold studies are safe tests. There are no side effects. The temperature changes you will be asked about are very minor and will not be uncomfortable.