Fire, police, and ambulance services were sent to a chemical incident in the Stoke Park area of town.
A man was taken to hospital after inhaling fumes from spilt chemicals in a domestic shed.
Police said the man was conscious when he boarded and ambulance and was talking to paramedics. He is not thought to be seriously affected.
Neighbouring residents were told to keep their windows and doors shut, but there was no need for them to evacuate their homes.
Five fire appliances and six or seven ambulances were called to the scene in Glamorgan Road at about 11.40am.
From his window, one resident of Maidenhall Approach witnessed emergency services rushing to the scene just before 12.30pm.
He said: “I saw four or five police cars, two fire engines, six or seven ambulances, the police helicopter and unmarked police cars. They were going up Maidenhall Approach, past the Smock pub, towards Asda.”
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here