Exposure to the sun

Everybody seems to like sunny weather. Sunlight is a source of natural light and energy. It is good for our general health, has healing properties and produces a feel good factor.

Many people travel abroad from the UK specifically in search of a sunnier climate. This is hardly surprising when you consider the sort of weather we often experience in a typical British summer.

Although sunbathing may be enjoyable it must always be remembered that excessive exposure to the sun's rays is a health hazard due to the harmful effects of ultraviolet radiation on the skin.

The sun emits two kinds of ultraviolet rays:

UVA - which penetrate deeply into the skin and can trigger allergies and cause premature ageing and wrinkling.
UVB - these affect the upper layers of the skin and trigger the production of melanin which causes tanning. Too much causes burning, freckling and thickening of the skin. They can also cause skin cancers.

They are both present when the sun shines and can both penetrate through cloud. Sun damage can also occur when sunlight is 'reflected' from water, sand or snow.

Sunburn often affects skiers, climbers and trekkers at high altitude where the intensity of the light increases by stealth. The higher the altitude,the more concentrated the sun's UV rays. Each 300 metre gain in altitude adds 4% to the sun's intensity.

The sun's rays can also penetrate through water and are effectively magnified. In shallow water the rays can reflect off a sandy bottom. Being underwater can therefore be deceptive due to the cooling effect of the water.

Snorkelers should always wear a tee shirt or similar to prevent the sun burning their backs. Scuba divers are not normally at risk due to their protective clothing and they are often too deep for harmful UV penetration.

Sunburn when it occurs is a major cause of distress to travellers and can have long-term effects including skin cancer and premature skin ageing. Over exposure to the sun can also dehydrate the skin.

Remember: Sunburn is always preventable.

Vulnerable Groups include:

  • Fair skinned people who very often have red or white hair and blue eyes.
  • Those persons with certain medical conditions such as albinism, lots of moles or a previous skin cancer.
  • Those on certain medications such as tetracyclines or diuretics.
  • People with certain skin conditions such as psoriasis, eczema and vitiligo need to take special care when they are in the sun.
  • The elderly, babies and young children are particularly sensitive.

General precautions

Everyone should avoid the midday sun, usually from noon until 2pm (3pm in the tropics).

Adults should wear a broad brimmed hat, long sleeved shirts and sunglasses. Children should wear long sleeved shirts, hats and high-factor waterproof sunscreen. Babies under 9 months should be kept out of direct sunlight.

Never lie in the sun to dry off after swimming, the skin will burn in a matter of minutes.

High altitude climbers etc. should wear a hat with a neck cover and sunglasses with nose shields and blinker side pieces.

Wear cotton fabrics next to the skin, they are cooler. Avoid loose weave fabrics that allow penetration of the sun's rays.

Sun factor preparations

Sun factor preparations work by reducing or blocking the effects of sunlight allowing a person to stay in the sun longer. Everyone who intends exposing themselves to direct sunlight should consider using a preparation with an appropriate Sun Protection Factor.

These absorb ultraviolet B (UVB) and to a lesser extent ultraviolet A (UVA).

The Sun Protection Factor (SPF) refers to the protection against UVB and will be marked on the outside of the container. Factors range from 2 to as high as 50.

With no protection, most people's skin will start to burn after 10 minutes exposure to the sun. The sun protection factor allows you sunbathe longer in safety without burning e.g. An SPF 8 allows approximately 8 times longer sun exposure, an SPF 15 allows 15 times longer etc.

There is now a star system denoting UVA protection where more stars indicates greater protection.(1 star lowest, 4 stars highest).

Always re-apply preparations after swimming, even if they are waterproof. The effectiveness of the protection will always decrease after immersion in water.

N.B. The re-application of a given factor does NOT mean that the protection time is doubled.

Sun block preparations

To find out which Sun Protection Factor you need:

These preparations are based on zinc oxide or titanium dioxide and are applied thickly to particularly sensitive areas like the lips and nose. They block out the sun's harmful rays by forming a reflective barrier.

They are particularly useful for persons going to high altitude where the rays are more intense, and are also popular with certain sports people such as cricketers who spend long periods in the sun.

Treatment of sunburn

  • Get the person out of the sun.
  • Cool the skin where possible with cold running water, a cold shower or immersion in a cool to luke-warm bath.
  • Avoid direct pressure to the burnt area.
  • Give pain killers.
  • Apply calamine lotion, witch hazel or a proprietary after sun lotion. After sun is very effective at cooling, calming and moisturizing the skin, it will also help to prevent peeling.


This condition occurs when the body is unable to cool its core temperature sufficiently and overheats. It is manifest in two distinct ways:

Heat Exhaustion

Heat Stroke

These are both the result of hot weather or working in hot conditions. Heat stroke can be fatal and is often the result of heat exhaustion.

Heat exhaustion is characterized by:

  • Headache dizziness and nausea
  • Cramps in the limbs and/or abdomen
  • Profuse sweating with pale, clammy skin
  • Rapid, weak breathing and pulse

When someone is suffering from heat exhaustion, try to cool them down by removing them from direct sunlight into the shade. Lie them down and apply lukewarm (not cold) water with a sponge or similar. They should be encouraged to drink as much rehydration solution as they can take. Allow them to rest until they fully recover, monitoring closely for any signs of deterioration.

Heat stroke is a serious condition caused by failure of the body's natural thermostat resulting in an inability to cool itself down by normal means. It usually occurs as a result of exposure to very hot surroundings. The onset can be sudden, resulting in unconsciousness in a matter of minutes. Medical assistance should be sought as soon as possible.

The main signs of heat stroke are:

  • Headache, dizziness, confusion & restlessness
  • Hot, flushed, dry skin due to failure of sweating mechanism
  • Full, bounding pulse
  • Body temperature above 40C
  • Rapid deterioration in the level of response

When heat stroke occurs the main priority is to cool the patient down as quickly as possible but never use ice or very cold water to avoid thermal shock which could kill them.

Remove the patient from any heat source and wrap them in a cool, wet sheet and keep them well ventilated. Make sure the sheet remains wet. Monitor closely for signs of cardiorespiratory failure and be prepared to resuscitate if necessary. When the temperature drops below 38C the wet sheet can be removed but if their temperature begins to rise again, replace it and continue as before.