You could put tons of fabric softeners and perfumed detergents, if you wash with cold water, you may have bad smell on your clothes.
The reason is very simple: there are bacteria on our clothes and when we wash in cold water, they are not all destroyed. These bacteria are the cause of bad smells.
Bed sheets and home textiles (must be washed in very hot water), but always wash your clothes in lukewarm water. This way, you will avoid bad smell and will remove bacteria, you will have less chance of finding soap residues on your dark clothes and the ugly stains will be easily removed.
Source: simplemost · Photo Credit: Fotolia