Article D2223-111 of the French General Code of Local Authorities
The burial compartment has isothermal insulation such that the overall coefficient of heat transmission is no more than 0.7 watts per square metre per degree Kelvin. For an ambient temperature of 30° C, the burial compartment’s cooling system must enable an internal temperature of between 0° C and 7° C to be reached in no more than one hour, and then maintained between these values for at least nine hours….