There is a good reason why “heart rate” can swing the paediatric early warning score (PEWS) from orange to red necessitating a move to resus with the child. Tachycardia in an unwell child is caused by compensated shock until proved otherwise.

Normal heart rate values (from APLS handbook):

<1 yr of age             110-160
 1-2yrs                       100-150
 2-5yrs                         94-140
5-12yrs                        80-120
>12yrs                          60-100

Only when shock has been ruled out should you think about the effect that fever, pain, crying or salbutamol may be having on the child’s heart rate.