The rules are very clear, the wicket keeper is the only player allowed to wear gloves. All other players would incur a 5 run penalty every time they touched the ball while wearing gloves. This includes for instance taking off your hat in order to use it to catch the ball (I have seen this done in a park cricket match!).
See Law 41 in the rules of cricket
Law 41 (The fielder)
- Protective equipment
No member of the fielding side other than the wicket-keeper shall be permitted to wear gloves or external leg guards. In addition, protection for the hand or fingers may be worn only with the consent of the umpires.
- Fielding the ball
A fielder may field the ball with any part of his person but if, while the ball is in play he wilfully fields it otherwise,
(a) the ball shall become dead and 5 penalty runs shall be awarded to the batting side. See Law 42.17 (Penalty runs). The ball shall not count as one of the over.
Note that the point about protection for the hand or fingers has been the source of some minor controversy over the years. Cricketers frequently injure their fingers while fielding and will often be seen with fingers taped up or two fingers taped together to protect a damaged finger. Usually this is permitted without any comment as it can actually make fielding harder. However, some players have at times gone a bit over the top and used sports tape to such an extent that they may as well be wearing a glove. As the law above suggests, it is up to the Umpires to judge if the tape being used is only what is required for a specific injury or is being used to gain an advantage.
The other convention that does not appear explicitly in the rules but is always adhered to is that spin bowlers may not use any tape or covering on their bowling hand. This is because tape would allow a much better grip on the ball allowing the bowler to impart much more spin than otherwise. It is also a matter of conditioning since spin bowling a lot of overs leads to blistering and even bleeding at the point of contact between the fingers and the ball. It is part of the art of spin bowling to build up the toughness of the hand to cope with this, rather than covering it with tape.