The sun is strong throughout the year in the country. Proper care against sunburn must be constantly taken. Dehydration and loss of salt through perspiration are two other common problems for the unprepared traveller. Drink plenty of fluids and replace your salt loss and remember that alcoholic drinks make dehydration worse, not better . Make sure you pack clothing suitable for a warm humid climate.
MOSQUITOES
Due to the constant humid climate, mosquitoes tend to be present throughout the year. The three most significant diseases transmitted by mosquitoes are Malaria, Dengue Fever and Japanese B Encephalitis. To repel mosquitoes, ticks and other arthropods, apply an insect repellent containing DEET to your skin or clothing.
The risk of malaria for most tourists visiting Peninsular Malaysia is extremely small. There is insignificant risk in Kuala Lumpur, Penang and other major cities. However, in East Malaysia, the risk of malaria is present throughout the year. Even in these regions, the risk is mainly off the coastal plains and towards the border areas. Generally, prophylaxis is recommended for those visiting Sabah or Sarawak.
FOOD
Generally, the level of food hygiene throughout the country is high. However, make sure your food and drinking water are safe. Food from street vendors should be treated with care. Drink only bottled or boiled water, or carbonated (bubbly) drinks in cans or bottles. If possible, avoid tap water, fountain drinks, and ice cubes. Bring along iodine tablets and portable water filters to purify water if bottled water is not available. Also, wash your hands often with soap and water. As an extra precaution, bring along anti-diarrhoea medication and an antibiotic prescribed by your doctor to self-treat moderate to severe diarrhoea.
Recommended vaccines:Poliomyelitis (childhood booster), Tetanus (childhood booster), Typhoid (food & water borne diseases), Hepatitis A (food & water borne diseases).
For those venturing outside cities and towns, further recommended vaccines are Hepatitis B, Rabies, Japanese B Encephalitis, Tuberculosis and Meningitis. For those visiting Sabah and Sarawak, Malaria prophylaxis is strongly recommended.
If you are coming from, or have recently travelled in, South America or sub-Saharan Africa you must present a certificate of vaccination against Yellow Fever upon arrival in Malaysia.
Further Health, Insurance, and Safety Advice can be found here.