On our stainless steel kettles, the brackets for the handles are spot-welded onto the side of the Kettle (as is the chain attachment). If your stainless steel kettle takes a heavy knock causing the spot welds to fail and one side of the handle (or the entire handle!) to come loose, then it may be possible to do a quick fix and keep boiling ;-) We have seen a whole variety of ways to fix this .....Glues can work, e.g. Superglue, Loctite, or other Metal glues. Can use a heat resistant glue but the temperature on the outside of the kettle is not particularly high.
We have seen large jubilee clips used to strap the brackets on!
Other people have actually removed the handle completely to make the kettle fit into tight spaces (Kayaks/Bikes/Rucksacks, etc.). We have seen leather straps/old belts (something with grip that doesn't slip easily) wrapped around the top ('shoulder' where the handles are normally attached) of the kettle. When paired with a soft rope or light wire handle this methods works nicely!
Another useful idea if removing the handle is to place a Neoprene sleeve/jacket around the upper part of the kettle - and attached some sort of fabric/rope handle to that. In addition to packing slightly smaller, users advise that the neoprene helps the kettle boil faster. But 30 seconds or a minute faster really wouldn't put me up nor down when I'm relaxing and looking forward to a cuppa. :-) The neoprene would however give the kettle a little protection against knocks and scrapes. ;-)
And of course you could spot weld the bracket back on (a local car mechanic might be able to spot weld the stainless steel)
Hopefully you never need to use any of these tips, but if you run into trouble with your handle - know that there are options available ;-)