1.Add a transparent border
[class*="col-"] {
background-clip: padding-box;
border: 10px solid transparent;
}
2. Use Row
<div class="row">
<div class="col-md-6">
<div class="col-md-12">
Set room heater temperature
</div>
</div>
<div class="col-md-6">
<div class="col-md-12">
Set room heater temperature
</div>
</div>
</div>