Last month guest columnist was Dr Claire Uebbing, a full-time general practitioner at the International SOS Clinic. Her answers to readers’ questions were published in the lifestyle section of the Phnom Penh Post on November 07, 2012.

Many people in Phnom Penh drink powdered sachets such as Royal D in order to get nutrients. Is this really a healthy way of getting vitamins?

Royal D, and other sachets like it, are designed to help replace fluids you lose through vomiting or diarrhea. They contain sugar, salts lsuch as sodium and potassium, and sometimes a little Vitamin C or Vitamin A. They are not a good source of nutrition, but if you are unable to drink anything else because of sickness, it is better than drinking just plain water.

If you are a serious athlete and sweat a lot during exercise, you may also use the sachets to replace some of the fluids and electrolytes you lose through sweat.

The best way to get enough vitamins and minerals however, is to eat a healthy, well-balanced diet.

This means a good amount and variety of fruits and vegetables, dairy products, meats and carbohydrates. Vitamins are absorbed much better when eaten in food than via pills or supplements.

I want to donate blood in Phnom Penh. How safe is it, and where is best to do it? Are there any particular requirements?

In Phnom Penh, you can donate blood at the National Blood Bank and Transfusion Centre. It is located in St 41 (Norodom Boulevard), at the corner of St 114, S/K Phsaar Thmei Muoy, Khan Doun Peenh, Phnom Penh.

This is probably the safest place to give blood in Cambodia. However, it is always wise to watch the nurses/technicians to make sure they use alcohol swabs and clean needles. In the past, these operations have been overseen by foreign aid agencies, so they should be up to the same standards, but we do not have any current updates on this.

In general, you are not able to give blood if you have HIV, hepatitis B or C, use intravenous recreational drugs or engage in high-risk sexual practices.  When you go, you will have to fill out a questionnaire to determine whether you are eligible.

Even though your intentions in donating blood are good, do your best to fill out the questionnaire honestly, even if you think it might make you ineligible.

Your blood will be screened for disease and will be thrown away if it is positive for any of the above.

You do not want to put health care workers at risk, and it will be a waste of time and resources for both you and the staff at the blood bank. There are well-documented blood shortages in Cambodia, however, and if you can help alleviate those shortages, by all means please do!

I have heard that it’s better to use a fan to keep cool at night than to sleep with air-conditioning on. Are there any health risks from using air-conditioning?

Air-conditioning can help you relax and sleep better because it reduces humidity in the room and controls the temperature more accurately.

However, air-conditioning units cool air by passing it through coils with refrigerant in them, and during this process both evaporation and condensation occur. The water vapour produced within the coils is an ideal medium for bacteria and mould growth.  

Bacteria and mould, as well as dust and pollens, can collect in air-conditioning units and then be blown into the air when turned on. So, unless AC units are cleaned regularly, they can become a reservoir for these harmful agents.

It’s not very common for bacteria to grow, but every few years there are reports of outbreaks of legionella pneumonia and aspergillosis due to this cause.  

Air-conditioning units also work by de-humidifying the air. The air is cool and dry, but can sometimes cause problems for people with asthma and allergies. People tend to have more asthma attacks in cool air — and, if there is dust or other allergens in the air, more allergy problems as well. 

Of course, fans can collect dust too, so it’s important to always keep things clean.