Heat Stroke can occur to any one and is basically your body over heating. This occurs when your body is unused to dealing with a sudden change in climate. The more time you spend in a hot climate the more your body will adapt and become capable of dealing with heat. The pores in your skin will open out as your body adapts to the heat and so the bodies ability to cool it self through sweat will increase. Care should especially be taken when you first arrive in a hot destination.
The main effects are a lack of energy, headaches, irritability and feeling too hot or cold
The best prevention is to let your body adapt slowly to the new climate and refrain from doing too much physical activity. It is important to make sure that you drink plenty of liquids to avoid dehydration. Wearing long sleeved tops, trousers and a hat will help prevent heat stroke.
To help your body adapt quickly if your room has air-conditioning leave it turned off you may have a couple of uncomfortable nights, but your body will adapt much quicker and you will quickly get used to the heat.
Where possible keep out of the sun especially during the heat of the day
If some one gets heat stroke then the most important thing to do is to cool them down. Wrap them in a sheet or clothing and spray them with water the evaporating water will lower their body temperature. They will also probably need to be treated for the effects of dehydration.