In regards to the campaign in support of the NHS was never intended as large scale event. As stated by experts of Trading Standards Institute (Code of Practice – Sky Lanterns, 2014) “When used as intended in appropriate conditions and in small numbers, sky lanterns do not constitute a high risk. With a little care and consideration they can be enjoyed safely."
PS. We have never said to use LED tea-lights with sky lanterns, for obvious reasons. LED tea lights do NOT produce any heat which is the basic physic principle to enable the lantern to fly.