Sir – Last year, during a two-month period of unusually warm weather, six people drowned in former quarry lakes in the UK, and warmer weather heralds an increase in young people and adults entering quarries uninvited, with potentially tragic consequences, reinforced by two fatalities in quarry lakes and a serious injury following a fall from a quarry rock face this year.

With the start of the school summer holidays, the Mineral Products Association is appealing to parents to ensure children are not tempted to enter quarries and gravel workings, of which there are a number, both active and disused, in West Oxfordshire.

Quarry lakes or other open water like reservoirs may look inviting but the temperature of the water can be ice-cold, extremely deep and conceal unexpected hazards beneath the water.

The impact that cold water can have on the body can result in even experienced swimmers suddenly finding themselves in trouble and the water can be difficult to exit.

Other dangers include unstable or concealed cliff edges that could give way, falling rocks, stockpiles that can collapse when children tunnel into them and settling ponds that can act like quicksand.

Quad and trail biking in quarries exposes riders to the risks from unstable ground collapsing or being hit by plant or machinery.

Please visit our Facebook page, Stay Safe Stay Out of Quarries. Our message and the message from the parents of the boys who have been killed is simple: please stay safe and Stay Out Of Quarries.

Elizabeth Clements, Mineral Products Association, London