Police are investigating three fires in Corby - including one which left two people in need of hospital treatment.
Four people had to escape after a rubbish fire spread to a nearby house at Llewellyn Walk at about 2.30am on Sunday.
The blaze damaged both the inside and outside of the house and one of the occupants and a neighbour who tried to help had to be taken to Kettering General Hospital after inhaling smoke.
It followed two other fires at Lingfield Walk at about 11.30pm on Thursday - when a wheelie bin and a pile of rubbish were set alight outside a house - and at Bizzy Bees Minibus Hire at St James Road, when a temporary office building was destroyed.
Police say they do not currently have reason to believe the fires are linked but are appealing for information.