Among Thai people, it's far more common for us to drink whiskey and beer than wine as an alcoholic drink. The reason is simple, wine is very expensive, grapes don't grow well here in Thailand and so it's largely imported from abroad. We do grow a lot of rice and a lot of sugar and both are perfect to make spirits.
There are quite a few varieties, some made from distilled fermented rice (Similar to Sato), but most are fermented molasses, closer to rum than whiskey.
In the Thai supermarkets (see the picture above), you've probably thought these are beers, they have a pull tab cap like a beer, but watch out, these are whiskeys, not beer. Some are as strong as fortified wine or rum, others are as strong as distilled spirit. The proof is right there on the label.... but in Thai numbers. The red one here is 28 degree proof, the green one 30 degree proof, about 3 times stronger than beer.
It's a myth that they contain opium or poisons. They're regulated like any other food/beverage, they are just a distilled spirit made from fermented rice/molasses, sometimes with added herbs to improve the flavour and colour. It's the hot sun and high sugar, high alcohol, content that can lead to problems. It's easy to drink them in excess, as though they were beer. Once out in the sun, you need to cool off or you will overheat, and alcohol also needs to be burned off, making things worse. Unwary drinkers simply overheat and suffer mild heat stroke. So drink in moderation, and eat a gop-gam dish along with the drink, like Thai people do, and serve with a mixer, Soda water is common, cola or similar mixers.