Solar noon is the middle point of the day between sunrise and sunset. In the UK summer solar noon is 1pm. This is why we advise seeking shade between 11 and 3.

When you're abroad you can find out what time the sun rises and sets by:

• looking in local newspapers
• searching on the internet
• enquiring at the tourist information office
• asking local people.

The sun's rays are at their strongest around solar noon. So this is when you need to be extra careful with sun protection. Seek shade if possible. Otherwise cover up with hat, sunglasses and clothing, use factor 15+ sunscreen and take extra care with children.

The manufacturers of P20 sunscreen claim that you only need to apply it once a day. However, they also explain that the product does not protect against UVA rays. This is perpetuating an old belief that it is UVB which is responsible for both sunburn and increasing your risk of skin cancer. However, we now know that UVA not only ages your skin, it also increases your risk of skin cancer.

We recommend using factor 15+ sunscreen that is labelled 'broad spectrum'. Broad spectrum sunscreen offers protection against both UVA and UVB. P20 sunscreen is not broad spectrum.

No sunscreen can offer 100% protection from UV rays. So we recommend that you use sunscreen as the last line of defence. In addition to sunscreen, spend time in the shade between 11 and 3 and cover up with a hat, sunglasses and clothing.

CancerHelp UK has more information about once-a-day sunscreens.

Most sunscreen will last 2-3 years but over time sunscreens do become less effective. This is why manufacturers add expiry dates to the bottles. Do not use a sunscreen that is past its expiry date.

However, it is not just time that affects how a sunscreen ages. Exposing sunscreen to extremes of temperature, such as in a hot car, can also reduce its effectiveness. Try to store sunscreen below 25°C.

The cost of sunscreen does not reflect how effective it is. Sunscreen manufacturers use similar methods to rate how much protection from UV rays their sunscreens offer. UVB protection is expressed as the SPF (sun protection factor). UVA protection is most often expressed as the star rating in the UK.

Choose a sunscreen with an SPF 15+ that is also labelled broad spectrum (this means it offers UVA protection). See our stay safe section for more on choosing a sunscreen.

Value Added Tax (VAT) of 17.5% is added to the price of sunscreens in the UK. However, there is no VAT on essential items such as food, books and children's clothing. Some people feel that we should not have to pay VAT on sunscreen because it is an essential item.

The SunSmart campaign has not yet had a chance to address this toipc in depth. Removing VAT from sunscreens is a complicated issue that involves not only the UK government but also the European Union. We hope to provide more information about VAT on sunscreens in the future.

The SunSmart campaign doesn't recommend any specific brands of sunscreen. But we can offer you advice about what to look for.

First of all, try sunscreens that are fragrance free and specially made for sensitive skin or children.

Sunscreens are made up of one or both of the following:

• chemical absorbers - these penetrate the skin and absorb sunlight
• physical reflectors - these sit on the top layer of skin and reflect sunlight.

Physical reflectors that sit on the top layer of skin are less likely to irritate your skin. However, they may leave a white sheen. Because of the white sheen people tend to apply less sunscreen, which means you receive less protection.

Ask your pharmacist for advice on which sunscreen is right for you.

If you have very sensitive skin test a small amount of sunscreen on a patch of your skin before applying it to your whole body. And remember that shade, hats and protective clothing have an important role to play in protecting your skin from the sun.

To get the most out of your factor 15+ sunscreen remember to:

• apply sunscreen 15-30 minutes before going out in the sun
• apply generous amounts of sunscreen to clean dry skin and rub in lightly
• reapply once outside to ensure even coverage
• then re-apply every 2 hours or more frequently if you wash, swim, rub your skin or sweat the sunscreen off
• put on make-up or insect repellent after using your sunscreen.

It is also important to bear in mind that you should never use sunscreen to spend longer in the sun. This puts you at risk of sunburn and skin damage.

As always, don't forget to seek shade between 11 and 3, and wear a hat, sunglasses and protective clothing.

SunSmart recommends factor 15+ sunscreen for use in the UK. We came to this decision with the help of expert advice from scientists and health professionals.

Higher factor sunscreens offer some extra protection from burning but tend to be more expensive. Factor 15 seems to offer the best balance between protection and price. You will get over 90% protection from UVB rays with SPF 15. Above SPF30 you don't get much additional protection from higher factors. It is also important to use a sunscreen that is labelled 'broad spectrum'. This means it offers UVA protection.

But remember that no sunscreen, no matter how high the factor, can offer 100% protection.