It was one or two in the morning when I stepped into the bathroom at my high-rise luxury hotel. And there it was, a cockroach big enough to star in a science-fiction movie. On general principles, I reported the intruder to the desk clerk the next morning.

"How large was it?" he asked.

Truthfully sticking with the reality rather than the effect, I indicated some three to four inches.

"Oh, ho!" said the clerk, "you shouldn't have told me. When they're that big we have to charge for double occupancy."

I suspect his man will rise in his profession. But his comments also struck the right chord. In the tropics, you'll keep if you bring along a grin-and-bear-it attitude to deal with less-than-happy surprises.

Everywhere in the world, of course, you'll come across occasional gaps in living standards ane amenities. But somehow, in the hot, hot places, there are a few you may encounter with some regularity. To be sure, plenty of tropics travelers never experience a single inconvenience, yet for peace of mind there are things it's best to know before you go. For instance:

When you hotel room contains a candle, it's not a hint to go to church: Actually it's a test-your-memory device. The idea is to remember where the candle is so that you can reach it in the dark. In candle-equipped hotel rooms, chances are higher than average that there will be some unexpected "dark." It's called Power Failure, and in some placed it even occurs on a regular timetable. It can be a little awkward if you're in an elevator or under a hairdryer, but since there's nothing you can do about it, it won't help if you panic.

Telephones are not necessarily instruments of communication: I don't know, maybe Alexander Graham Bell was mistreated in his youth and really invented the telephone for revenge. If so, he must be reasonably pleased that in more than a few tropical parts, it is diabolical how many "wrong numbers" you can dial and how many cutoffs and busy signals you can get. The main thing to remember is to unload the telephoning chore on someone else whenever possible. At the same time, when full understanding is crucial, it's often safer to visit rather than call places like airline offices.

Be prepared for roommates: They're not the norm but neither are they unheard of. Just the other day I noticed a deluxe tour package that includes a stay at a "fine hotel" in a certain Indian city. I know that fine hotel and you couldn't meet with nicer treatment - but you might also meet some rodents. I did, anyhow. They were the long, gray sort. One ran over my foot in the bar, but the one that truly tried me was the one that shared my room.

Waking in the night, I turned on the light and discovered this nervy, fourfooted creature nibbling at some papers I had beside my bed. I don't know which of us was more flustered, but he bolted first - into the bathroom and straight down an open floor drain. Since then, I've made it a rule to keep the door shut on open-drain bathrooms to knock before entering.

Roaches and waterbugs occasionally invade even the very newest and very best hotel bathrooms, I've discovered. It's therefore not a bad idea to give up going barefoot so that you're always wearing a weapon.

Mostl likely to live in, though, are lizards. But fear not, they're fiends. They eat mosquitoes and other pests and, as a rule, keep well out of your way.

Eventually most tropics travelers learn to keep luggage closed and locked - which actually is good strategy anywhere these days for all sorts of reasons. Where there's wild life, it's also practical to store shoes on a shelf and to up-end or shake wearing apparel before climbing into it.

Yes, there still is such a thing as sunstroke: Possibly the least-heeded warning in the world is: "Serious sunburn may come from very little exposure," but that doesn't make it less true. Travelers who come from colder climates persist in thinking all suns are the same, and run around bare-headed for overly long periods, underestimating the effects of sunshine even on cloudy days.

What they should be doing is drinking lots of liquids, taking frequent showers, wearing loose clothing and instantly treating all wounds, no matter how small. Comfort also come with open, open shoes, though closed ones - with socks - are still necessary for rough walking.

Not all beaches are beautiful: Even when you see the local piling in, it does not necessarily follow that the water is safe. In fact, some of the world's "best" beaches are scandalously polluted - the biggest scandal being the fact that they are unposted. You may, in fact, find it impossible to get a straight story.

The wise move in any case is to rule out swimming at beaches adjacent to hihgly populated areas where there's the possibility of untreated sewage disposal. Pools are preferable (if they're well chlorinated), and so is everything you can do to avoid swallowing any water.