If you are in one of the temperature hot spots, getting a good night's sleep may be a challenge right now.
So to help turn the nightmare around, University of Otago sleep researcher Professor Barbara Galland gives a few tips on sleeping well through the heat.
Prof Galland tells Checkpoint most of the strategies are actually common sense, but there are some important reminders that can help bring down your body temperature so your sleep cycle isn't disrupted.
"Many have a lot less sleep [during hot days] and a lot of disrupted sleep and potentially crankiness the next day for a lot of people.
"You really have to pay a lot of things to actually pull your body temperature down overnight."
During the day, stay hydrated because that can help regulate your body temp overnight - and Galland warns people too much alcohol can actually cause dehydration.
For the night, dress lightly and comfortably and thinking about some light and cotton for your bedding too, she says.
"The research shows anything between 15.6 and 19.4 [degrees] to be exact is what most people can regulate their [body] temperature at.
"The main thing is to also really make sure your head and face are clear, because we get rid of a lot of the body temperature through the face and head."
"I don't know exactly what the optimum would be [for thread count on sheets], but the sheets need to be able to breathe, if you like, to get rid of that body temperature through them ... so the fabric is actually quite important for that to be able to dissipate your body heat.
"Thinking about the under-bedding too, some people may still have their woollen under-blanket on their bedding from winter time."