The hottest time of the day and the time of maximum burning are two different things. The most intense solar radiation comes at Local Apparent Noon. This is not necessarily the same time as noon on the clock unless you live on the meridian of your time zone. The highest levels of solar radiation are an hour or so either side of this and this is the time you are most likely to get burnt..
The hottest time of the day is later in the afternoon. The sun heats the Earth which, in turn, heats the lower troposphere. The incoming solar radiation starts each day at zero at sunrise, reaches a maximum at noon and falls back to zero at sunset. The warm earth also radiates out into space and continues to do this at night. If you plot the incoming solar radiation on a graph together with the outgoing terrestrial radiation, you will see that the two lines cross twice, once a couple of minutes after sunrise when the coldest part of the day occurs and it crosses again in the afternoon, usually between 3pm and 4pm, when the hottest part of the day occurs. While incoming solar radiation is greater than the outgoing terrestrial radiation, the temperature rises. When the terrestrial radiation is greater than the solar radiation, the temperature falls.