Temperature Issues

So I've got a Brupaks Linthwaite Light fermenting at the moment but thanks to my latest gadget I have noticed that the temperature has been getting a bit high during the days. The max temp has been up near 30 for the past couple of days...

I'm putting it down to the aquarium heater I hang in the brew being on the fritz possibly. Guess I'll have to check it out in some water after this brew is bottled. This will no longer be a problem after I've sorted my temperature control cupboard (a fridge with a heater in it and one of these). There will be more on this in the future...