All* UK domestic sockets must be RCD protected.
It is not possible to overload a UK socket due to the fused plug arrangement.
Most British houses were wired before RCD's were introduced. At that time, RCD (CGFI) outlets had also not become mainstream. In the US, CGFI's were code in 1968 in wet areas (pools, bathrooms e.t.c.) with full modern code introduced in 1980. Therefore, many appliances are plugged into non RCD type sockets in this country, especially dangerous for garden appliances and bathroom appliances like hairdyers, straighteners e.t.c. which would be safer plugged into a RCD socket in a bathroom than in a non-RCD socket somewhere else/near the bathroom.
It IS possible to overload a twin 13a socket. 2x13a loads in one TWIN socket=26 amps. Brick-type two or 3-way adaptors allow even more 13a plugs in one socket without an integral fuse, hence the scorching commonly found on dishwasher/tumble dryer twin sockets.
Tumble dryers ARE the main cause of house fires in the UK. Google "tumble dryer fires UK". I lose count of the number of new-build homes and rental properties I've stayed in that have unbelievable laundry arrangements with multiple appliances plugged into 4-way adaptors in "utility rooms". Another main cause is hair straighteners placed on beds and left on by accident because we don't have sockets in bathrooms here, if we did, the hot appliance would be placed on a bathroom countertop and cause no danger. Often, hairdryers have a thermal cutout and turn themselves off if you've been using them too long. People often throw them on the bed because they've stopped working, leave, then later on, the cutout resets and they come back on and set fire to the bed.
In the US, there is a HUGE range of insulation-suitable downlight fittings widely available, even to the DIYer (as most hardware stores stock them). In the UK, you are extremely limited and have to order them. Buildings regulations are also very vague and contradicting about insulation protection to downlights. Part L requires continual insulation across the roof space, whilst electrical regs require sufficient airspace around downlights, with no proprietary products actually achieving both requirements, short of DIY 'boxes' to enclose the light. 'Fire rated' lights simply mean they prevent the spread of fire between floors, they do not mean that can't cause a fire if in contact with insulation or timber.