Prostrating in a cap or turban, or when wearing gloves

The scholars are agreed that it is better for a worshipper’s
forehead and hands to touch the ground directly when he prostrates, except
when he has an excuse. 

They differed as to whether that is obligatory. Imam
al-Shaafa’i was of the view that it is obligatory, but the majority of
scholars are of the view that it is mustahabb only, and is not obligatory. 

Al-Nawawi (may Allaah have mercy on him) said, explaining the
views of the scholars on this issue: 

The views of the scholars with regard to prostrating on one’s
sleeve, hem, hand, the end of one’s turban or anything else that is attached
to the person. We have mentioned that our view is that it is not correct to
prostrate on any of these things. This is also the view of Dawood and of
Ahmad, according to one report. 

Maalik, Abu Haneefah, al-Awzaa’i, Ishaaq and Ahmad (according
to the other report) said that it is valid. The author of al-Tahdheeb
said: This is the view of the majority of scholars. They quoted as evidence
the hadeeth of Anas (may Allaah be pleased with him) who said: We used to
pray with the Messenger of Allaah (peace and blessings of Allaah be
upon him) when it was intensely hot, and if one of us could not bear to
place his forehead on the ground, he would spread out his garment and
prostrate on it. Narrated by al-Bukhaari and Muslim.  

It was narrated that Ibn ‘Abbaas (may Allaah be pleased with
them) said: I saw the Messenger of Allaah (S) on a rainy day, avoiding the
mud when he prostrated by placing a garment that he was wearing beneath his
hands. Narrated by Ibn Hanbal in his Musnad.  

It was narrated that al-Hasan said: The companions of the
Messenger of Allaah (peace and blessings of Allaah be upon him) used to
prostrate with their hands inside their garments, and a man would prostrate
on his turban. Narrated by al-Bayhaqi. 

And he said: The scholars are unanimously agreed that it is
preferable for the forehead to touch the ground directly when prostrating.
End quote from al-Majmoo’, 3/397-400 

Ibn Qudaamah (may Allaah have mercy on him) said: The
worshipper does not have to touch the ground directly with any part of his
body. Al-Qaadi said: If he prostrates on the end of his turban, or on his
sleeve or hem, his prayer is valid according to one report. This is the view
of Maalik and Abu Haneefah. Those who allow prostrating on one’s garment
when it is too hot or too cold include ‘Ata’, Tawoos, al-Nakha’i, al-Sha’bi,
al-Awzaa’i, Maalik and Ishaaq. 

Prostrating on the end of one’s turban was allowed by
al-Hasan, Makhool, and ‘Abd al-Rahmaan ibn Yazeed. Shurayh prostrated on his
burnous. 

End quote from al-Mughni, 1/305 

Shaykh Ibn ‘Uthaymeen
(may Allaah have mercy on him) was asked: If a worshipper prostrates and
puts his turban down as a protection between him and the ground, what is the
ruling on his prayer? 

He replied: The prayer
of that worshipper is valid, but he should not use his turban as a
protection between him and the ground except in cases of need, such as when
the ground is very hard, or there are stones that may hurt him, or thorns.
In that case there is nothing wrong with protecting himself from the ground
with something that is attached to him, such as his turban or clothing,
because Anas ibn Maalik (may Allaah be pleased with him) said: We used to
pray with the Prophet (peace and blessings of Allaah be upon him) when
it was very hot, and if one of us could not put his forehead on the ground,
he would spread out his garment and prostrate on it. This indicates that it
is better to let the forehead touch the place of prostration directly, but
there is nothing wrong with a man protecting himself from the ground with
something that is attached to him such as his garment or turban, if there is
a need for that because the ground is very hot or very cold, or it is rough.
But he should remember that it is also essential to allow the nose to touch
the ground as well in this case, because of the hadeeth of Ibn ‘Abbaas (may
Allaah be pleased with him) who narrated that the Prophet (peace and
blessings of Allaah be upon him) said: “I have been commanded to prostrate
on seven bones: the forehead” – and he pointed to his nose –“ the hands, the
knees and the ends of the feet.” End quote. 

Fataawa al-Shaykh Ibn ‘Uthaymeen,
13/question no. 519 

And Allaah knows best.