Newcastle upon Tyne
Dr Larry Goodyer replies: Fortunately your father is at little risk of catching malaria during his visit. Malaria is now only a problem in one part of Malaysia, namely Sabah (on the island of Borneo), so malaria tablets need not be taken if visiting other parts of the country.
However, it would still be a good idea to avoid mosquito bites during the daytime, as dengue fever is a potential hazard. He will probably need to have vaccinations against hepatitis A and typhoid, as well as checking he is up to date with tetanus and polio.
Otherwise, the main risk to health would be from gut infections. Diarrhoea is very common among travellers to the tropics, but the risk can be minimised by sensible eating and drinking habits.
Follow the golden rule of "peel it, boil it, cook it, or forget it" and drink bottled or boiled water. Carrying chemical tablets to disinfect water as a standby can also be useful. If your father does get a bout of diarrhoea, oral rehydration sachets are the best form of treatment.
It would also be advisable for your father to seek the advice of his doctor about whether he is fit to fly. People who have severe chronic lung diseases, such as emphysema, can experience problems.
Dr Larry Goodyer is a lecturer in clinical pharmacy at King's College, London. Contact the Nomad Travel Health Helpline (tel: 0891 633414; calls cost 50p per minute).