Roles of the skin

Your skin performs a number of important functions that help keep the rest of your body in check. These include:

  • Protection
  • Temperature control
  • Sensation
  • Vitamin D production


Your skin is your body's first line of defence against external threats, such as sunlight, cold weather, dirt, dust and viruses. It provides your body with a robust barrier of protection from injury and infection.

Temperature control

The blood vessels, hairs and sweat glands in your skin play a vital role in managing your body temperature.

When you are hot and need to cool down, the blood vessels in your skin expand and allow heat to escape. You also start sweating and your hairs lie flat to allow the escaping heat to pass out of the body.

When you are cold and need to retain heat, the opposite happens. Your blood vessels tighten, you produce far less sweat and your hairs stand on end in an attempt to trap warm air around your body.


Your skin is home to numerous nerve endings and receptors that sense changes and allow you to feel objects, sense pain and pressure and differentiate hot from cold.

Vitamin D production

When you expose your skin to the sun it produces vitamin D. Your body needs vitamin D to keep your bones and muscles strong and healthy.

Small amounts of sunlight will increase vitamin D levels and keep your bones healthy. But spending too much time in the sun exposes the skin to ultraviolet (UV) radiation which can cause skin damage that can lead to skin cancer. Vitamin D comes from two sources: UV rays from the sun and our diet.

To help meet your vitamin D needs the World Health Organisation recommends getting 5 to 15 minutes of casual sun exposure to hands, face and arms two to three times a week during the summer months.  However, skin cancer is the most common cancer in Ireland. 

It is mainly caused by the same UV ray that is needed for our body to produce vitamin D.

Never increase your risk of skin cancer to meet your vitamin D needs, so:

  • Never let your skin redden or burn
  • Never use a sunbed to increase your vitamin D levels
  • Take extra care when in the sun if you have fair skin because fair skin burns more quickly when exposed to UV rays

Always Remember:

  • Cover up - Wear a t-shirt, long shorts and a hat that gives shade to the face, back of neck and ears
  • Seek shade - Especially from 11am to 3pm
  • Wear wraparound sunglasses - Make sure they give UV protection
  • Wear sunscreen - Using sunscreen with SPF 15 or higher and UVA protection

More information on the Irish Cancer Society website

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