It has been long regarded that Hydronic heating is one of the safest, most hygienic ways to heat your home.
There is no danger of burning or scalding since the system is fully enclosed with radiator temperatures well below boiling point. However, the surface temperature of a radiator can be quite hot to touch, so care should be taken with anyone who may not be able to adequately feel surface temperature and react when coming into contact with the radiator.
As it is radiant heat and there is no circulation of dust and allergens, hydronic heating is the ideal heating system for the elderly, children, and pets.
Natural convectors are a safer alternative to radiators if required, as the surface temperature of natural convectors is pleasantly warm to touch, never reaching a higher surface temperature than that of a radiator.
Yes, most houses can have hydronic heating installed as a retrofit option, however, houses built on a concrete slab are more difficult to undertake due to lack of access for the required pipe work.