There has been no known example of transmission as a result of giving or receiving first aid. The theoretical risk is very low in the context of ordinary good practice in delivering first aid.

Any theoretical risk from mouth to mouth resuscitation is extremely low indeed. But resuscitation using mouthpieces may be more effective if you are trained in their use and they are available.

The only risk would be from infected blood. But this would have to get inside your own bloodstream in order to infect you. The Red Cross has advised that `safe handling of blood in first aid situations does not require 'space suits' or excessively high levels of protection.'

Existing standards of good practice are designed to protect both the giver and receiver of first aid from much more infectious germs than HIV.

These existing standards are also designed to protect you irrespective of who's involved. Remember, that for each person whom you know or think has HIV, there are going to be several others whom you don't know about. So relying on knowledge of peoples' antibody status is dangerously irrelevant. And it would be unethical to refuse first aid to anyone on those grounds.

Instead, the best precaution is making sure that:

• You're satisfied you've had adequate training.
• You understand the proper procedures.
• You're supplied with all the necessary infection control equipment such as disposable gloves and aprons, paper towels, bleach and other disinfectants, etc.
• You stick to the proper procedures.
• You report any incidents, problems or concerns to your supervisor or adviser.

Training in first aid is available from the British Red Cross or St John's Ambulance Brigade.