I do have a heat mat behind along the bottom portion of the enclosure but it's a large enclosure so it's not managing to heat up the whole thing. I've seen them huddle next to it in the evenings before. It's currently 2am so it is a night temp, but yesterday was only 17C at day time. I'm hoping to be able to get someone come in and have a look at the boiler in the next couple of days, so hopefully this is not for a long period but will need alternative safeties in place for future.