Husband putting me and DS at risk due to colleagues?

[jogonlll]

We have a 2yo DS. My DH works in a hospital admin dept, his team is a small one - him and 3 women. One of the women had a sick daughter (they think glandular fever, but who knows) and has had to self isolate. She's returning to work on Monday, after just 10 days of isolation. Her and my DH are set to work together in a small room (less than 2m square) all day Monday. He says generally at work they can't follow the 2m rule due to space restrictions.

I've freaked out and told him I don't want him working on Monday (to avoid said woman) and he's being hugely blasé and saying "it'll be fine" and "i'll be careful" etc.

AIBU?

How does he plan to be careful?

10 days is quite high for nhs
My mate works in a&e as it’s 7 days always even if it’s a family member that’s ill and you’re isolating - I think it’s because of their important role and also given that people generally have symptoms by 7 days if they were going to catch it

To be fair they symptoms of glandular fever are fairly distinct from cononavirus and given the mean time to show symptoms is five days . I think I'd be ok with this.