Monitors need at least a 130 to 140 degree hot spot... They will bask in these areas for short periods of time through out the day...

Even other reptiles use very hot basking spots...

I have caught garters, corns, milks, pines, and other colubrids basking in temps well into the 90's and sometimes in the 100 degree range... I always bring a temp gun when I go herping...

These high basking spots are very important for digestion and for metabolism functions...

Many care sheets you read on the internet are shakey at best... Many are full of out dated, regurgitated info, and lots of misconceptions...