81 A riot control vehicle with mounted water cannons • Water cannons should never be used to disperse a peaceful assembly; • A warning must be given to the participants in the assembly before water cannons are used; • W hile suited to use in policing static assemblies, their use should be avoided in relation to mobile assemblies or moving marches; • Adequate dispersal or exit routes must be available to enable people to move away safely; • Water cannons should never be used against individuals who are in danger of being knocked off buildings [or other elevated positions]; • Medical care must be available to those who require it; and • Water cannons should never be used in sub-zero temperatures. The handbook also highlights that the presence of a water cannon can be seen as intimidating or as a provocation by the participants in the assembly, and that the use of water cannons can create health and safety risks, such as rendering ground surfaces very slippery, or by causing falls and injury when high water pressure is used.