Restricted input type for number only by using HTML5

How to make the input type to be valid for number only? We do not need to use javascript, because we can do that easily with HTML5.

Let say we want to make an input type for temperature with the following rule: minimum 30^o and maximum 50^o, but allowing to input one decimal digit.
The example is 30.1^o.

Read: Getting current total and previous one from MySQL

To do that we can make HTML code like below:

<input id="temperature" class="form-control" max="50" maxlength="4" min="30" name="temperature" size="50" step="0.1" type="number" />

type="number" is used to make the input type is valid for number only.
step="0.1" is used when clicking on up/down button.
min="30" max="50" is the minimum and maximum number so the form can be submitted.

The result of the example above is like below:

DEMO

Read: Getting current total and previous one from MySQL

Good luck.