I started doing insides as soon as tradesmen were allowed. But on my terms. As people's standards are all over the place. Some have been so complacent throughout the worst of the lockdown.
P3 respirator, safety specs, disposable gloves. Then change of clothes, or at least shirt and then have a shower at home. An apron is a bit too much but probably should leaning over kitchen sides and bathroom sinks. Putting PPE on and taking it off all done in the right order and hands are sanitised and cloths and trad tools are not reused the same day. You've gotta be on the ball to avoid cross contamination. Pretending you've got it on your hands
and tools helps, without becoming paranoid of course.
When you come into someone's house a lot seem loose all sense of perspective and do not social distance whatsoever. They get right up to you and get in your way. Not all of them but that's definitely what I noticed.
Surgical mask is only one way protection, P3 level respirator works both ways. Have got a GVS half mask with replaceable filters.
I'm taking no risks. Even though the percentages are low, plenty of people in my age group (later 30s) that got seriously ill and took weeks to recover. I don't want to become a statistic. Even if I was perfectly fine I don't want to be getting into a 2 week+ quarantine because someone in the household discovered they've got it.
It wasn't half hot in summer though.