The following things are allowable for a fasting person to do:
- Taking a bath and pouring cold water over oneself, as well as gargling to cool and moisten the mouth and tongue.
- Hijaamah (Cupping) and anything that resembles it,  so long as it doesn’t lead to weakness, for then it would be disliked (makrooh).
“The Prophet received Hijaamah while he was fasting.” [Reported by Al-Bukhaaree]
As for the hadeeth:
“The person doing the Hijaamah and the one receiving the Hijaamah may break their fast”
then it is abrogated, for that used to be in the beginning of Islaam.
- Using the Siwaak (tooth-stick). This is based on the generality of the Prophet's saying:
“If it were not that I would be putting my nation to hardship I would have ordered them to use the Siwaak along with every wudoo.” [Reported by Al-Bukhaaree]
The person who is fasting is not exempted from this because the Siwaak is highly recommended at all times without exception – in Ramadaan and out of Ramadaan, before the sunrise and after it.
- Delaying the bath (ghusl) that is necessary after sexual intercourse (from the previous night) until after Fajr starts: It is authentically reported that“The time for Fajr would come in while the Prophet was in a state of Janaabah (sexual impurity) from his wives. So he would bathe (perform ghusl) and fast.” [Reported in Al-Bukhaaree and Muslim]
- Kissing, embracing and fondling the wife, without having sexual intercourse. This is unless the man fears for himself that he will fall into the act of intercourse, for then he must avoid this. 'Aa'ishah (رضي الله عنها) reported that:
“Allaah's Messenger would kiss and embrace (his wives) while he was fasting. But he had more power to control his desires than any of you.” [Reported by Al-Bukhaaree and Muslim]
- Applicable medicines (such as creams or injections) that do not go to the stomach, so long as they do not serve the purpose of food and drink 
- Using kohl (a black substance applied to the eyelids) and eye-drops
- Swallowing one’s saliva or its likes, which normally flow from the mouth or the nose to the throat. 
The person who is fasting must beware of going too deep when inhaling water (up the nose or mouth) during wudoo, based on the saying of the Prophet:
“Go deep when inhaling water (during wudoo) unless you are fasting.” [Reported by the collectors of the Sunan with an authentic chain of narration]
 Such as the opening of a vein, a blood transfusion and a blood discharge.
 Such as glucose and other nutritious injections that flow directly through the blood, for even though it does not go to the stomach, it still serves as food and drink. So fasting is not valid with it.
 Such as mucus or the dust that floats in the atmosphere, as well as all that one is not able to repel from inhaling, since Allaah will not hold a person accountable for something that he has no control over.