Our 2.5 tog Grobag Baby Sleep Bags are ideal for Autumn, Winter and Spring and can be used right up until the Summer nights become warm. If your nursery is usually below 20°C, we recommend a 2.5 tog Grobag. However, if you live in a particularly mild region or if you have well insulated and heated accommodation and your nursery is usually 21°C or above, you may prefer a 1.0 tog Grobag for year round use. Our 1.0 tog Grobags are ideal for use from during the Summer months when the nights are warmer and are also very useful in early Spring and Autumn for day-time naps whilst your baby is still in a 2.5 tog Grobag at night. 0.5 tog Grobag Baby Sleep Bags are for use in high Summer, for holidays abroad, or if your child is unwell and has a raised temperature.