AN INFRARED thermal gun can give you a thorough understanding of where your house is losing heat in winter, or gaining it in summer.

The more you know about where heat is entering or leaving your home, the more effective you'll be at controlling energy consumption and waste. With an infrared thermal gun, you just wander around the inside and outside of your home and take readings at windows, outside doors, walls, or wherever else heat may leak through.

The device helps you get a complete picture of problems with insulation, sealing, or windows in need of replacement. With £1 in £3 spent on household energy being thrown away, you have the potential to save as much as £461 per year with the right glazing.

Trinity Mirror Southern, publishers of the Chronicle and Gazette series, has teamed up with Safestyle UK to mark World Energy Day on June 5 by giving away five infrared thermal guns. Simply answer the following question:

When is World Environment Day?

a) June 5th
b) July 4th
c) August 1st

Email your answer to Steve.Bax@trinitymirror.com and don't forget to include your full name, address and a day time phone number in case you win. Entries must be in by midnight on Tuesday June 5th 2012. Usual TMS terms and conditions apply and the editor's decision is final.