But it's also the time of year when you can't go outside after about 10am without the fear of melting, especially with the heatwave conditions across Canberra in the past fortnight.

This presents a dilemma, and potentially some pretty serious health risks.

ACT Health's Paul Dugdale said the official medical advice was that exercising outdoors during extreme heat should be avoided.

"Plan your day around the heat and avoid being outdoors between 11am and 3pm at least," Dr Dugdale said.

It is worth checking the temperature prior to exercising outdoors as through Wednesday to Friday the hottest part of the day was between 3pm and 6pm, with temperatures exceeding 36 degrees at times.

He said the biggest risks of exercising or being outdoors during extreme heat were sunburn, dehydration and overheating.

Canberra professional cyclist Chloe Hosking, who was home training over Christmas, tried to avoid exercising in the middle of the day during summer.

"It's just horrible," Ms Hosking said.

"There's some races you can't get away from [the heat].

"I remember the world championships in Qatar we were racing in 42 degree heat."

During the world championship road race, in which Ms Hosking came seventh, she used a Camelback and consumed more than 10 bottles of water.

"I drank so much and my body couldn't take any more water in and I just started throwing it up," she said.

Although she's been doing five-hour long training rides over the summer break, Ms Hosking said she heads off from home at 5.30am to avoid the heat.

She said she will consume at least one bottle of water per hour while exercising in summer and uses electrolytes more regularly.

"My biggest piece of advice is unless you're a professional avoid exercising in the heat," she said.

"You'll probably do more damage than good."

Dr Dugdale echoed these sentiments, pointing to the Australian Open which will soon captivate the country.

"You can’t just emulate your heroes, they are trained and seasoned athletes with coaching and a health team around them," he said.

"You need to start training and train all year round and get to know how you perform in different conditions.

“If you’re inexperienced in [a sport] you’re going to be more prone to dehydration or overheating."

Australian Open organisers have implemented a new heat policy ahead of this year's event which, if it reaches its highest score, will see play abandoned, emphasising the risk posed even to professionals from heat stress.

Dr Dugdale said signs of heat stress to look out for, at any time, but particularly during exercise are feeling dizzy or faint, headaches and dark urine.

"You can get confused and that is quite dangerous because you might keep going when you shouldn’t because you’re not recognising the signs," he said.

He said there were alternatives to exercising in the heat such as air conditioned gyms, swimming and even taking a long walk around a shopping mall.

He stressed it was crucial if you are going to exercise to remain vigilant over how you and others you are with are coping in the conditions and stop, rehydrate and cool down if you experience any adverse reactions.