Top-left panel: JWST NIRSpec spectrum of B1-c in the 3.8 4.2 μm range highlighting the detection of HDO ice. Laboratory spectra of HDO amorphous ice (HDO(a)) as well as of CH₃ OH ice are overlaid. A Gaussian has been added to represent an S-H ice feature. Top-right panel: Ice band of ¹³CO₂ 4.38 μm of B1-c highlighting the lack of a heated ice component. Bottom-left panel: JWST NIRSpec spectrum of the high mass protostar IRAS 20126 taken from Slavicinska et al. (2024) showing the detection of both amorphous and crystalline HDO ice. The laboratory spectrum of crystalline HDO ice is shown in pink (HDO(c)). Bottom-right panel: Ice band of ¹³CO₂ 4.38 μm of IRAS 20126 showing evidence of a heated ice component as analyzed by Brunken et al. (2024a).