A warning has been given to front line police about wearing stab resistant body armour (SRBA) that could pose threat to their health.

As believed by Napier constable Grant Marshall, he was affected by kidney stones due to wearing the armour, which made him being absent from work for many weeks. He iterated the same in a letter to the Police Association magazine, Police News.

``We all know how hot we can get in them. They are designed to `wick' the sweat away from the body, it works against our body's natural cooling process'', said Marshall. He added that they were advised to take two litres of water daily but his urologist recommended police to take three litres of water.

He expressed that due to kidney stones, he suffered from intense pain that made him so uncomfortable to sit, stand or lay. His main aim in writing this letter was to motivate the police to drink plenty of water so as to counterbalance the effect of wearing armour. He also advised police staff to take off the armour shirt as often as they could.