Brian wrote:

Quite simply place the ends in very hot water for a couple of minutes. They
will soon soften for fitting and then tighten as they cool...



I use 0.4" drip line with connectors that you push the drip line onto
and tighten a threaded cap over them so they won't slip off. The drip
lines are just a bit smaller than the widest part of the connector so
that they will fit tightly. This makes them hard to get on. I put them
on as best I can, then turn on the water. Most of them leak at that
point. I then go back and loosen the cap and push them on the rest of
the way. The water pressure keeps the drip line open so that it doesn't
kink up when I'm trying to push it on. The system has a filter and
pressure regulator so that I don't get so much flow that it sprays all
over me while I'm handling a leaking connection, but I do get wet
occasionally. However I have always dried off afterwards with no lasting
damage.

I rarely have hot water available when I'm in the field.