A travel mosquito net is possibly the single most important way to stay healthy when you travel in the tropics (not to mention sleeping soundly, as opposed to spending the night swatting the nightlife). Remember, over half a million people are infected by malaria mosquitoes each year.
A mosquito net also keeps other critters out, like creepy crawlies or falling geckoes.
I wouldn't dream of traveling without one when heading for any warm, humid places.
It's especially important if you're traveling on a budget. Air conditioning helps keep mosquitoes at bay but I often stay in huts or out of doors - and there's nothing to protect you then.
To be effective a mosquito net should have a close mesh - about 120-200 holes per square inch or 1.2 mm x 1.2 mm is considered the best.
While cotton may seem more natural, it collects dampness and weighs more than a synthetic fiber so I'd opt for the polyester type nets.
There are two types of insect net: one with a frame, and one without. Lets start with the standard travel mosquito net - without a frame.
The typical insect nets are squares or rectangles of insect netting with a ring (or two) that you attach to a wall or ceiling. It should be wide enough to be tucked under the mattress without touching you. If it touches your skin, the mosquito can simply land on it and bite you!
The advantage of this type of net is that it's light to carry in your pack and takes up little room. You can easily wash it and hang it out to dry.
There's also a disadvantage: you actually need something to hang it on. Many rooms in developing countries have nails or hooks on which you can fasten a net - but not always (although these days there are new, nylon mounts that fasten themselves to the wall without damaging it). It's disconcerting to walk into a room net in hand to find no hook. You're not going to start hammering a hook into someone else's wall, are you...
So that's where mosquito net tents come in. I have not one, but two of these, just in case I lose one. That's how important it is to me!
The mosquito net tent has two advantages. First, it's free-standing, which means no worries about nails or hooks. And second, it's properly sealed, which means mosquitoes can't get in under or around it.
Actually, there's a third advantage: if you're traveling really cheaply, most net tents have a plastic base, which'll keep out any additional critters that might have found a home on the bed...
The other major question about choosing a travel mosquito net is whether to go for one with a permethrin treatment or whether to opt for a simple untreated net.
The advantage of permethrin, a strong synthetic chemical, is its effectiveness. Most mosquitoes won't survive contact with it so you'll have fewer chances of being bitten. Permethrin treatment isn't permanent - you'll have to retreat the net (and your clothes, if you spray them) every so often.
While it's not known to be toxic to humans (keep it away from your pets - it can kill them), many people abhor chemicals and simply refuse to use them if at all avoidable.
I wouldn't dream of heading to the tropics without my travel mosquito net. These tents are easy to find online. For those who have been writing and asking about my net, the model I've been using for years is the Longroads Travel Tent. Other popular models with travelers include the Eco-Keeper Bed Bug Tent, Atwater Carey Tropic Screen II Mosquito Net and Kamp-Rite Insect Protection System.
Even if at times rooms have their own mosquito nets, check them carefully. Years of wear and tear may have left holes in the net - and if mosquitoes can get in, the net will be useless.
Remember, avoiding malaria and dengue fever should be right at the top of your travel health list!