As with all bondage, basic health considerations (i.e. not leaving the tied person alone) need to be taken. However, because of the amount of skin covered, you need to take special care to prevent overheating and dehydration. Especially rubber and latex will trap virtually all body heat.

Sleep sacks come in two basic variants - with the arms inside or outside. Arm inside models are essentially very tight sleeping bags. Arm outside are more like a bag for the legs combined with a straitjacket top.
The bottom part is usually very restricting, often with special cuffs for the ankles. Some arm inside models have additional cuffs for restriction of the hands and arms while others rely on handcuffs. The sleep sack is closed with a zipper that usually ends below the head. A hood usually completes the attire.

Aside from improvised sleep sacks made from sleeping bags, leather, rubber, latex and spandex are the most common materials.

Leather sleep sacks are very common because of the strength of the material. Leather does not stretch and allows for easy integration with a collar and additional cuffs. The strength of leather also allows the subject to be suspended in the sleep sack. Proper fit is very important.

Rubber sleep sacks allow for more movement than leather. Since rubber needs to be combined with other materials to implement cuffs, it is often impossible to find rubber sleep sacks with a lot of possibilities for restraint. Rubber traps body heat and fluids so be very careful with overheating.

Latex latex sleep sacks are very rare and need to be handled with special care because of the sensitivity of the material. Only arm outside models are available in latex.