Use a working platform - emergencies only!
If it is necessary to elevate a person for maintenance purposes then a properly designed and constructed working platform should be used. Use of such a platform should be restricted to emergencies only and should follow the HSE guidance note PM28. More details here.
Disclaimer. The legislative information contained on this web site is my interpretation of the law based on many years in the health and safety business. A definitive interpretation can only be given by the courts. I will therefore not be held responsible for any accident/incident/prosecution arising as a consequence of anyone using any information obtained from this web site.